教师招聘
It’s one of our common beliefs that mice are afraid of cats. Scientists have long known that even if a mouse has never seen a cat before, it is still able to detect chemical signals released from it and run away in fear. This has always been thought to be
题目
It’s one of our common beliefs that mice are afraid of cats. Scientists have long known that even if a mouse has never seen a cat before, it is still able to detect chemical signals released from it and run away in fear. This has always been thought to be something that is hard-wired into a mouse’ s brain.
But now Wendy Ingram, a graduate student at the University of California, Berkeley, has challenged this common sense. She has found a way to “cure” mice of their inborn fear of cats by infecting them with a parasite, reported the science journal Nature.
The parasite, called Toxoplasma gondii, might sound unfamiliar to you, but the shocking fact is that up to one-third of people around the world are infected by it. This parasite can cause different diseases among humans, especially pregnant women—it is linked to blindness and the death of unborn babies.
However, the parasite’s effects on mice are unique. Ingram and her team measured how mice reacted to a cat's urine (尿) before and after it was infected by the parasite. They noted that normal mice stayed far away from the urine while mice that were infected with the parasite walked freely around the test area.
But that's not all. The parasite was found to be more powerful than originally thought—even after researchers cured the mice of the infection. They no longer reacted with fear to a cat's smell, which could indicate that the infection has caused a permanent change in mice's brains.
Why does a parasite change a mouse's brain instead of making it sick like it does to humans The answer lies in evolution.
“It’s exciting scary to know how a parasite can manipulate a mouse's brain this way,"Ingram said. But she also finds it inspiring. "Typically if you have a bacterial infection, you go to a doctor and take antibiotics and the infection is cleared and you expect all the symptoms to also go away,” she said, but this study has proven that wrong. “This may have huge implications for infectious disease medicine."
The experiment found that mice infected with toxoplasma gondii__________.查看材料
But now Wendy Ingram, a graduate student at the University of California, Berkeley, has challenged this common sense. She has found a way to “cure” mice of their inborn fear of cats by infecting them with a parasite, reported the science journal Nature.
The parasite, called Toxoplasma gondii, might sound unfamiliar to you, but the shocking fact is that up to one-third of people around the world are infected by it. This parasite can cause different diseases among humans, especially pregnant women—it is linked to blindness and the death of unborn babies.
However, the parasite’s effects on mice are unique. Ingram and her team measured how mice reacted to a cat's urine (尿) before and after it was infected by the parasite. They noted that normal mice stayed far away from the urine while mice that were infected with the parasite walked freely around the test area.
But that's not all. The parasite was found to be more powerful than originally thought—even after researchers cured the mice of the infection. They no longer reacted with fear to a cat's smell, which could indicate that the infection has caused a permanent change in mice's brains.
Why does a parasite change a mouse's brain instead of making it sick like it does to humans The answer lies in evolution.
“It’s exciting scary to know how a parasite can manipulate a mouse's brain this way,"Ingram said. But she also finds it inspiring. "Typically if you have a bacterial infection, you go to a doctor and take antibiotics and the infection is cleared and you expect all the symptoms to also go away,” she said, but this study has proven that wrong. “This may have huge implications for infectious disease medicine."
The experiment found that mice infected with toxoplasma gondii__________.查看材料
A.stayed far away from cat’s urine
B.moved around the area freely and tearlessly
C.because more sensitive to cat's smell
D.were more afraid of cats
B.moved around the area freely and tearlessly
C.because more sensitive to cat's smell
D.were more afraid of cats
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相似问题和答案
第1题：
请阅读Passage l。完成第21—25小题。
Passage 1
It's one of our common beliefs that mice are afraid of cats. Scientists have long known that even if a mouse has never seen a cat before, it is still able to detect chemical signals released from it and run away in fear. This has always been thought to be something that is hard-wired into a mouse s brain.
But now Wendy Ingram, a graduate student at the University of California, Berkeley, has challenged this common sense. She has found a way to"cure" mice of their inborn fear of cats by infecting them with a parasite, reported the science journal Nature.
The parasite, called Toxoplasma gondii, might sound unfamiliar to you, but the shocking fact is that up to one-third of people around the world are infected by it. This parasite can cause different diseases among humans, especially pregnant women--it is linked to blindness and the death of unborn babies.
However, the parasite's effects on mice are unique. Ingram and her team measured how mice reacted to a cat's urine(尿) before and after it was infected by the parasite. They noted that normal mice stayed far away from the urine while mice that were infected with the parasite walked freely around the test area.
But that's not all. The parasite was found to be more powerful than originally thought—even after researchers cured the mice of the infection. They no longer reacted with fear to a cat's smell,which could indicate that the infection has caused a permanent change in mice's brains.
Why does a parasite change a mouse's brain instead of making it sick like it does to humans?
The answer lies in evolution.
"It's exciting scary to know how a parasite can manipulate a mouse's brain this way," Ingram said. But she also finds it inspiring."Typically if you have a bacterial infection, you go to a doctor and take antibiotics and the infection is cleared and you expect all the symptoms to also go away."
She said, but this study has proven that wrong."This may have huge implications for infectious disease medicine."
The passage is mainly about__________.
查看材料
Passage 1
It's one of our common beliefs that mice are afraid of cats. Scientists have long known that even if a mouse has never seen a cat before, it is still able to detect chemical signals released from it and run away in fear. This has always been thought to be something that is hard-wired into a mouse s brain.
But now Wendy Ingram, a graduate student at the University of California, Berkeley, has challenged this common sense. She has found a way to"cure" mice of their inborn fear of cats by infecting them with a parasite, reported the science journal Nature.
The parasite, called Toxoplasma gondii, might sound unfamiliar to you, but the shocking fact is that up to one-third of people around the world are infected by it. This parasite can cause different diseases among humans, especially pregnant women--it is linked to blindness and the death of unborn babies.
However, the parasite's effects on mice are unique. Ingram and her team measured how mice reacted to a cat's urine(尿) before and after it was infected by the parasite. They noted that normal mice stayed far away from the urine while mice that were infected with the parasite walked freely around the test area.
But that's not all. The parasite was found to be more powerful than originally thought—even after researchers cured the mice of the infection. They no longer reacted with fear to a cat's smell,which could indicate that the infection has caused a permanent change in mice's brains.
Why does a parasite change a mouse's brain instead of making it sick like it does to humans?
The answer lies in evolution.
"It's exciting scary to know how a parasite can manipulate a mouse's brain this way," Ingram said. But she also finds it inspiring."Typically if you have a bacterial infection, you go to a doctor and take antibiotics and the infection is cleared and you expect all the symptoms to also go away."
She said, but this study has proven that wrong."This may have huge implications for infectious disease medicine."
The passage is mainly about__________.
查看材料
A．mice' s inborn terror of cats
B．the evolution of Toxoplasma
C．a new study about the effects of a parasite on mice
D．a harmful parasite called Toxoplasma gondii
B．the evolution of Toxoplasma
C．a new study about the effects of a parasite on mice
D．a harmful parasite called Toxoplasma gondii
答案：C
解析：
根据文章第二段“She has found a way t0‘cure’mice of their inborn fear of cats by infecting them with a parasite。reported the science iournal Nature．”可知，Berkeley发现了一种通过让老鼠感染寄生虫来改变它们天生害怕猫的方法。文章下面的内容也都是围绕着这个新发现来阐述的．故选C。
第2题：
请阅读Passage l。完成第21—25小题。
Passage 1
It's one of our common beliefs that mice are afraid of cats. Scientists have long known that even if a mouse has never seen a cat before, it is still able to detect chemical signals released from it and run away in fear. This has always been thought to be something that is hard-wired into a mouse s brain.
But now Wendy Ingram, a graduate student at the University of California, Berkeley, has challenged this common sense. She has found a way to"cure" mice of their inborn fear of cats by infecting them with a parasite, reported the science journal Nature.
The parasite, called Toxoplasma gondii, might sound unfamiliar to you, but the shocking fact is that up to one-third of people around the world are infected by it. This parasite can cause different diseases among humans, especially pregnant women--it is linked to blindness and the death of unborn babies.
However, the parasite's effects on mice are unique. Ingram and her team measured how mice reacted to a cat's urine(尿) before and after it was infected by the parasite. They noted that normal mice stayed far away from the urine while mice that were infected with the parasite walked freely around the test area.
But that's not all. The parasite was found to be more powerful than originally thought—even after researchers cured the mice of the infection. They no longer reacted with fear to a cat's smell,which could indicate that the infection has caused a permanent change in mice's brains.
Why does a parasite change a mouse's brain instead of making it sick like it does to humans?
The answer lies in evolution.
"It's exciting scary to know how a parasite can manipulate a mouse's brain this way," Ingram said. But she also finds it inspiring."Typically if you have a bacterial infection, you go to a doctor and take antibiotics and the infection is cleared and you expect all the symptoms to also go away."
She said, but this study has proven that wrong."This may have huge implications for infectious disease medicine."
The experiment found that mice infected with toxoplasma gondii__________.
查看材料
Passage 1
It's one of our common beliefs that mice are afraid of cats. Scientists have long known that even if a mouse has never seen a cat before, it is still able to detect chemical signals released from it and run away in fear. This has always been thought to be something that is hard-wired into a mouse s brain.
But now Wendy Ingram, a graduate student at the University of California, Berkeley, has challenged this common sense. She has found a way to"cure" mice of their inborn fear of cats by infecting them with a parasite, reported the science journal Nature.
The parasite, called Toxoplasma gondii, might sound unfamiliar to you, but the shocking fact is that up to one-third of people around the world are infected by it. This parasite can cause different diseases among humans, especially pregnant women--it is linked to blindness and the death of unborn babies.
However, the parasite's effects on mice are unique. Ingram and her team measured how mice reacted to a cat's urine(尿) before and after it was infected by the parasite. They noted that normal mice stayed far away from the urine while mice that were infected with the parasite walked freely around the test area.
But that's not all. The parasite was found to be more powerful than originally thought—even after researchers cured the mice of the infection. They no longer reacted with fear to a cat's smell,which could indicate that the infection has caused a permanent change in mice's brains.
Why does a parasite change a mouse's brain instead of making it sick like it does to humans?
The answer lies in evolution.
"It's exciting scary to know how a parasite can manipulate a mouse's brain this way," Ingram said. But she also finds it inspiring."Typically if you have a bacterial infection, you go to a doctor and take antibiotics and the infection is cleared and you expect all the symptoms to also go away."
She said, but this study has proven that wrong."This may have huge implications for infectious disease medicine."
The experiment found that mice infected with toxoplasma gondii__________.
查看材料
A．stayed far away from cat's urine
B．moved around the area freely and tearlessly
C．because more sensitive to cat's smell
D．were more afraid of cats
B．moved around the area freely and tearlessly
C．because more sensitive to cat's smell
D．were more afraid of cats
答案：B
解析：
根据文章第四段“They noted that normal mice stayed far away from the urine while mice that were infected with the parasite Walked freely around the test area．”可知，受到寄生虫感染的老鼠能够自由随意地在测试区域周围走动．故选B。
第3题：
I haven't seen him for quite a long time, but his parents ______ him sometimes.
A. still saw
B. still see
C. have still seen
D. has still seen
正确答案：B
18．答案为B 句中的sometimes表明有时见过他，句中谓语要用一般现在时。
18．答案为B 句中的sometimes表明有时见过他，句中谓语要用一般现在时。
第4题：
共用题干
第一篇
A meager（不足的）diet may give you health and long life, but it's not much fun一and it might not even be necessary. We may be able to hang on to most of that youthful（有青春活力的）vigor （精力）even if we don't start to diet until old age.
Stephen Spindler and his colleagues from the University of California at Riverside have found that some of an elderly mouse's liver genes can be made to behave as they did when the mouse was young simply by limiting its food for four weeks. The genetic rejuvenation（恢复活力，返老还童） won't reverse other damage caused by time for the mouse,but could help its liver metabolize（使进入新陈代谢过程）drugs or get rid of toxins.
Spindler's team fed three mice a normal diet for their whole lives,and fed another three on half-rations.Three more mice were switched from the normal diet to half-feed for a month when they were 34 months old一equivalent to about 70 human years.
The researchers checked the activity of 11,000 genes from the mouse livers,and found that 46 changed with age in the normally fed mice.The changes were associated with things like inflammation and free radical production一probably bad news for mouse health.In the mice that had dieted all their lives,27 of those 46 genes continued to behave like young genes.But the most surprising finding was that the mice that only started dieting in old age also benefited from 70 percent of these gene changes.
"This is the first indication that these effects kick in pretty quickly",says Huber Warner from the National Institute on Aging near Washington D.C.
No one yet knows if calorie restriction works in people as it does in mice,but Spindler is hopeful."There's attracting and tempting evidence out there that it will work,"he says.
If it does work in people,there might be good reasons for rejuvenating the liver. As we get older,our bodies are less efficient at metabolizing drugs,for example.A brief period of time of dieting,says Spindler,could be enough to make sure a. drug is effective.
But Spindler isn't sure the trade-off is worth it."The mice get less disease,they live longer,but they're hungry,"he says."Even seeing what a diet does,it's still hard to go to a restaurant and say:I can only eat half of that."
Spindler hopes we soon won't need to diet at all. His company,Lifespan Genetics in California, is looking for drugs that have the effects of calorie restriction.
第一篇
A meager（不足的）diet may give you health and long life, but it's not much fun一and it might not even be necessary. We may be able to hang on to most of that youthful（有青春活力的）vigor （精力）even if we don't start to diet until old age.
Stephen Spindler and his colleagues from the University of California at Riverside have found that some of an elderly mouse's liver genes can be made to behave as they did when the mouse was young simply by limiting its food for four weeks. The genetic rejuvenation（恢复活力，返老还童） won't reverse other damage caused by time for the mouse,but could help its liver metabolize（使进入新陈代谢过程）drugs or get rid of toxins.
Spindler's team fed three mice a normal diet for their whole lives,and fed another three on half-rations.Three more mice were switched from the normal diet to half-feed for a month when they were 34 months old一equivalent to about 70 human years.
The researchers checked the activity of 11,000 genes from the mouse livers,and found that 46 changed with age in the normally fed mice.The changes were associated with things like inflammation and free radical production一probably bad news for mouse health.In the mice that had dieted all their lives,27 of those 46 genes continued to behave like young genes.But the most surprising finding was that the mice that only started dieting in old age also benefited from 70 percent of these gene changes.
"This is the first indication that these effects kick in pretty quickly",says Huber Warner from the National Institute on Aging near Washington D.C.
No one yet knows if calorie restriction works in people as it does in mice,but Spindler is hopeful."There's attracting and tempting evidence out there that it will work,"he says.
If it does work in people,there might be good reasons for rejuvenating the liver. As we get older,our bodies are less efficient at metabolizing drugs,for example.A brief period of time of dieting,says Spindler,could be enough to make sure a. drug is effective.
But Spindler isn't sure the trade-off is worth it."The mice get less disease,they live longer,but they're hungry,"he says."Even seeing what a diet does,it's still hard to go to a restaurant and say:I can only eat half of that."
Spindler hopes we soon won't need to diet at all. His company,Lifespan Genetics in California, is looking for drugs that have the effects of calorie restriction.
What can be inferred about completely normally fed mice mentioned in the passage?
A:They will not experience free radical production.
B:They will experience more genetic rejuvenation in their lifetime.
C:They have more old liver genes to behave like young genes.
D:They are more likely to suffer from inflammation.
A:They will not experience free radical production.
B:They will experience more genetic rejuvenation in their lifetime.
C:They have more old liver genes to behave like young genes.
D:They are more likely to suffer from inflammation.
答案：D
解析：
第一段第一句讲“节食可能不是非做不可的事”，第二句讲“即使在年老以后才开始节食，我们也能保持大部分的青春活力”，因此，“我们必须从小就开始节食”是错误的，D是答案。
第二段提及“一只高龄老鼠”的时候，作者谈到，“只要连续四周限制一些衰老的老鼠进食，它们的肝脏基因就会变得和衰老前一样充满活力”。据此，“为了阐明节食对老鼠所产生的影响”最好地回答了题干中的问题。
第四段提到，“正常饲养的老鼠随着年龄的增长有46个肝脏基因会发生变化。这种变化与诸如炎症和体内自由基的产生有关”。因此D正确。
第四段最后一句讲“但最惊人的发现是那些上了年纪才开始节食的老鼠也能从70％的基因变化中受益”。“最惊人的”自然是“最令研究人员感兴趣的”。
文章的最后两段谈及Spindler对节食的看法。首先，他不能肯定节食是否值得；其次，他希望在不久的将来，我们不必节食。所以我们可以推知，他认为节食不是得以健康长寿的好办法。
第二段提及“一只高龄老鼠”的时候，作者谈到，“只要连续四周限制一些衰老的老鼠进食，它们的肝脏基因就会变得和衰老前一样充满活力”。据此，“为了阐明节食对老鼠所产生的影响”最好地回答了题干中的问题。
第四段提到，“正常饲养的老鼠随着年龄的增长有46个肝脏基因会发生变化。这种变化与诸如炎症和体内自由基的产生有关”。因此D正确。
第四段最后一句讲“但最惊人的发现是那些上了年纪才开始节食的老鼠也能从70％的基因变化中受益”。“最惊人的”自然是“最令研究人员感兴趣的”。
文章的最后两段谈及Spindler对节食的看法。首先，他不能肯定节食是否值得；其次，他希望在不久的将来，我们不必节食。所以我们可以推知，他认为节食不是得以健康长寿的好办法。
第5题：
请阅读Passage l。完成第21—25小题。
Passage 1
It's one of our common beliefs that mice are afraid of cats. Scientists have long known that even if a mouse has never seen a cat before, it is still able to detect chemical signals released from it and run away in fear. This has always been thought to be something that is hard-wired into a mouse s brain.
But now Wendy Ingram, a graduate student at the University of California, Berkeley, has challenged this common sense. She has found a way to"cure" mice of their inborn fear of cats by infecting them with a parasite, reported the science journal Nature.
The parasite, called Toxoplasma gondii, might sound unfamiliar to you, but the shocking fact is that up to one-third of people around the world are infected by it. This parasite can cause different diseases among humans, especially pregnant women--it is linked to blindness and the death of unborn babies.
However, the parasite's effects on mice are unique. Ingram and her team measured how mice reacted to a cat's urine(尿) before and after it was infected by the parasite. They noted that normal mice stayed far away from the urine while mice that were infected with the parasite walked freely around the test area.
But that's not all. The parasite was found to be more powerful than originally thought—even after researchers cured the mice of the infection. They no longer reacted with fear to a cat's smell,which could indicate that the infection has caused a permanent change in mice's brains.
Why does a parasite change a mouse's brain instead of making it sick like it does to humans?
The answer lies in evolution.
"It's exciting scary to know how a parasite can manipulate a mouse's brain this way," Ingram said. But she also finds it inspiring."Typically if you have a bacterial infection, you go to a doctor and take antibiotics and the infection is cleared and you expect all the symptoms to also go away."
She said, but this study has proven that wrong."This may have huge implications for infectious disease medicine."
The underlined part "hard-wired" in Paragraph 1 probably means__________.
查看材料
Passage 1
It's one of our common beliefs that mice are afraid of cats. Scientists have long known that even if a mouse has never seen a cat before, it is still able to detect chemical signals released from it and run away in fear. This has always been thought to be something that is hard-wired into a mouse s brain.
But now Wendy Ingram, a graduate student at the University of California, Berkeley, has challenged this common sense. She has found a way to"cure" mice of their inborn fear of cats by infecting them with a parasite, reported the science journal Nature.
The parasite, called Toxoplasma gondii, might sound unfamiliar to you, but the shocking fact is that up to one-third of people around the world are infected by it. This parasite can cause different diseases among humans, especially pregnant women--it is linked to blindness and the death of unborn babies.
However, the parasite's effects on mice are unique. Ingram and her team measured how mice reacted to a cat's urine(尿) before and after it was infected by the parasite. They noted that normal mice stayed far away from the urine while mice that were infected with the parasite walked freely around the test area.
But that's not all. The parasite was found to be more powerful than originally thought—even after researchers cured the mice of the infection. They no longer reacted with fear to a cat's smell,which could indicate that the infection has caused a permanent change in mice's brains.
Why does a parasite change a mouse's brain instead of making it sick like it does to humans?
The answer lies in evolution.
"It's exciting scary to know how a parasite can manipulate a mouse's brain this way," Ingram said. But she also finds it inspiring."Typically if you have a bacterial infection, you go to a doctor and take antibiotics and the infection is cleared and you expect all the symptoms to also go away."
She said, but this study has proven that wrong."This may have huge implications for infectious disease medicine."
The underlined part "hard-wired" in Paragraph 1 probably means__________.
查看材料
A．deeply rooted
B．quickly changed
C．closely linked
D．deeply hurried
B．quickly changed
C．closely linked
D．deeply hurried
答案：A
解析：
文章第一段指出老鼠即使没有见过猫也是会害怕的，可推断出这是天生就刻在老鼠脑子里的一种行为。deeplv rooted“深深根植于”符合文章想要表达的意思．故选A。
第6题：
请阅读Passage l。完成第21—25小题。
Passage 1
It's one of our common beliefs that mice are afraid of cats. Scientists have long known that even if a mouse has never seen a cat before, it is still able to detect chemical signals released from it and run away in fear. This has always been thought to be something that is hard-wired into a mouse s brain.
But now Wendy Ingram, a graduate student at the University of California, Berkeley, has challenged this common sense. She has found a way to"cure" mice of their inborn fear of cats by infecting them with a parasite, reported the science journal Nature.
The parasite, called Toxoplasma gondii, might sound unfamiliar to you, but the shocking fact is that up to one-third of people around the world are infected by it. This parasite can cause different diseases among humans, especially pregnant women--it is linked to blindness and the death of unborn babies.
However, the parasite's effects on mice are unique. Ingram and her team measured how mice reacted to a cat's urine(尿) before and after it was infected by the parasite. They noted that normal mice stayed far away from the urine while mice that were infected with the parasite walked freely around the test area.
But that's not all. The parasite was found to be more powerful than originally thought—even after researchers cured the mice of the infection. They no longer reacted with fear to a cat's smell,which could indicate that the infection has caused a permanent change in mice's brains.
Why does a parasite change a mouse's brain instead of making it sick like it does to humans?
The answer lies in evolution.
"It's exciting scary to know how a parasite can manipulate a mouse's brain this way," Ingram said. But she also finds it inspiring."Typically if you have a bacterial infection, you go to a doctor and take antibiotics and the infection is cleared and you expect all the symptoms to also go away."
She said, but this study has proven that wrong."This may have huge implications for infectious disease medicine."
Which of the following statements is true according to the passage?
查看材料
Passage 1
It's one of our common beliefs that mice are afraid of cats. Scientists have long known that even if a mouse has never seen a cat before, it is still able to detect chemical signals released from it and run away in fear. This has always been thought to be something that is hard-wired into a mouse s brain.
But now Wendy Ingram, a graduate student at the University of California, Berkeley, has challenged this common sense. She has found a way to"cure" mice of their inborn fear of cats by infecting them with a parasite, reported the science journal Nature.
The parasite, called Toxoplasma gondii, might sound unfamiliar to you, but the shocking fact is that up to one-third of people around the world are infected by it. This parasite can cause different diseases among humans, especially pregnant women--it is linked to blindness and the death of unborn babies.
However, the parasite's effects on mice are unique. Ingram and her team measured how mice reacted to a cat's urine(尿) before and after it was infected by the parasite. They noted that normal mice stayed far away from the urine while mice that were infected with the parasite walked freely around the test area.
But that's not all. The parasite was found to be more powerful than originally thought—even after researchers cured the mice of the infection. They no longer reacted with fear to a cat's smell,which could indicate that the infection has caused a permanent change in mice's brains.
Why does a parasite change a mouse's brain instead of making it sick like it does to humans?
The answer lies in evolution.
"It's exciting scary to know how a parasite can manipulate a mouse's brain this way," Ingram said. But she also finds it inspiring."Typically if you have a bacterial infection, you go to a doctor and take antibiotics and the infection is cleared and you expect all the symptoms to also go away."
She said, but this study has proven that wrong."This may have huge implications for infectious disease medicine."
Which of the following statements is true according to the passage?
查看材料
A．Toxoplasma gondii causes people strange and deadly diseases.
B．With certain infection the infectious disease cannot be cured completely.
C．Human beings infected by toxoplasma gondii will have permanent brain damage.
D．Toxoplasma gondii is harmful to human beings, but it does no harm to mice.
B．With certain infection the infectious disease cannot be cured completely.
C．Human beings infected by toxoplasma gondii will have permanent brain damage.
D．Toxoplasma gondii is harmful to human beings, but it does no harm to mice.
答案：B
解析：
寄生虫会对未出生的小孩造成致命性的伤害，故A排除；文章只表明这种感染对老鼠的大脑有永久性的改变，并没有提及人类，故C排除；寄生虫对人类有危害，但是并不能说明对老鼠没有危害，故D排除。文章最后一段指出．人们一旦受到细菌感染就希望吃抗生素来清除所有的感染并希望所有的症状都能消失．但是这种想法是错误的．也可以推断出B是正确的。
第7题：
请阅读Passage l。完成第21—25小题。
Passage 1
It's one of our common beliefs that mice are afraid of cats. Scientists have long known that even if a mouse has never seen a cat before, it is still able to detect chemical signals released from it and run away in fear. This has always been thought to be something that is hard-wired into a mouse s brain.
But now Wendy Ingram, a graduate student at the University of California, Berkeley, has challenged this common sense. She has found a way to"cure" mice of their inborn fear of cats by infecting them with a parasite, reported the science journal Nature.
The parasite, called Toxoplasma gondii, might sound unfamiliar to you, but the shocking fact is that up to one-third of people around the world are infected by it. This parasite can cause different diseases among humans, especially pregnant women--it is linked to blindness and the death of unborn babies.
However, the parasite's effects on mice are unique. Ingram and her team measured how mice reacted to a cat's urine(尿) before and after it was infected by the parasite. They noted that normal mice stayed far away from the urine while mice that were infected with the parasite walked freely around the test area.
But that's not all. The parasite was found to be more powerful than originally thought—even after researchers cured the mice of the infection. They no longer reacted with fear to a cat's smell,which could indicate that the infection has caused a permanent change in mice's brains.
Why does a parasite change a mouse's brain instead of making it sick like it does to humans?
The answer lies in evolution.
"It's exciting scary to know how a parasite can manipulate a mouse's brain this way," Ingram said. But she also finds it inspiring."Typically if you have a bacterial infection, you go to a doctor and take antibiotics and the infection is cleared and you expect all the symptoms to also go away."
She said, but this study has proven that wrong."This may have huge implications for infectious disease medicine."
The author's attitude towards the experiment is__________.
查看材料
Passage 1
It's one of our common beliefs that mice are afraid of cats. Scientists have long known that even if a mouse has never seen a cat before, it is still able to detect chemical signals released from it and run away in fear. This has always been thought to be something that is hard-wired into a mouse s brain.
But now Wendy Ingram, a graduate student at the University of California, Berkeley, has challenged this common sense. She has found a way to"cure" mice of their inborn fear of cats by infecting them with a parasite, reported the science journal Nature.
The parasite, called Toxoplasma gondii, might sound unfamiliar to you, but the shocking fact is that up to one-third of people around the world are infected by it. This parasite can cause different diseases among humans, especially pregnant women--it is linked to blindness and the death of unborn babies.
However, the parasite's effects on mice are unique. Ingram and her team measured how mice reacted to a cat's urine(尿) before and after it was infected by the parasite. They noted that normal mice stayed far away from the urine while mice that were infected with the parasite walked freely around the test area.
But that's not all. The parasite was found to be more powerful than originally thought—even after researchers cured the mice of the infection. They no longer reacted with fear to a cat's smell,which could indicate that the infection has caused a permanent change in mice's brains.
Why does a parasite change a mouse's brain instead of making it sick like it does to humans?
The answer lies in evolution.
"It's exciting scary to know how a parasite can manipulate a mouse's brain this way," Ingram said. But she also finds it inspiring."Typically if you have a bacterial infection, you go to a doctor and take antibiotics and the infection is cleared and you expect all the symptoms to also go away."
She said, but this study has proven that wrong."This may have huge implications for infectious disease medicine."
The author's attitude towards the experiment is__________.
查看材料
A．positive
B．subjective
C．negative
D．objective
B．subjective
C．negative
D．objective
答案：D
解析：
在整篇文章中，作者都是在客观地叙述Wendy Ingram的新发现。故选D。
第8题：
Passage Five
Many superstitious people are afraid of black cats. They believe that black cats have a strange power. If a black cat crosses their path, they think they will have bad luck.
Black cats haven't always had such a bad reputation. Long ago, the Egyptians thought that black cats were holy animals. They even worshipped them. Pasht was an Egyptian goddess who had a woman's body and a cat's head. Because the Egyptians had so much respect for black cats, they often buried the sacred creatures with great ceremony. Mummies of cats have often been found in ancient cemetery ruins. To keep the cats company after they died, mice were sometimes buried beside them.
Feelings about black cats have always been strong. People have thought they were either very good or very bad. The people of Europe, in the Middle Ages, believed black cats were the evil friends of witches and the Devil. Witches were said to have the power to change themselves into black cats. People believed that you could not tell whether a black cat was just a cat, or whether it was a witch disguising herself as she plotted some evil scheme. The brain of a black cat was thought to be a main ingredient in witch's brew.
Unlike their ancestors of the Middle Ages, Englishmen today consider black cats to be good luck charms. Fishermen's wives often keep a black cat around so that their husbands will be protected when they are out at sea.
52. The Egyptian goddess Pasht had a ______.
A. woman's head and a cat's body
B. woman's head and a lion's body
C. cat's head and a man's body
D. woman's body and a cat's head
正确答案：D
第9题：
共用题干
第一篇
A meager（不足的）diet may give you health and long life, but it's not much fun一and it might not even be necessary. We may be able to hang on to most of that youthful（有青春活力的）vigor （精力）even if we don't start to diet until old age.
Stephen Spindler and his colleagues from the University of California at Riverside have found that some of an elderly mouse's liver genes can be made to behave as they did when the mouse was young simply by limiting its food for four weeks. The genetic rejuvenation（恢复活力，返老还童） won't reverse other damage caused by time for the mouse,but could help its liver metabolize（使进入新陈代谢过程）drugs or get rid of toxins.
Spindler's team fed three mice a normal diet for their whole lives,and fed another three on half-rations.Three more mice were switched from the normal diet to half-feed for a month when they were 34 months old一equivalent to about 70 human years.
The researchers checked the activity of 11,000 genes from the mouse livers,and found that 46 changed with age in the normally fed mice.The changes were associated with things like inflammation and free radical production一probably bad news for mouse health.In the mice that had dieted all their lives,27 of those 46 genes continued to behave like young genes.But the most surprising finding was that the mice that only started dieting in old age also benefited from 70 percent of these gene changes.
"This is the first indication that these effects kick in pretty quickly",says Huber Warner from the National Institute on Aging near Washington D.C.
No one yet knows if calorie restriction works in people as it does in mice,but Spindler is hopeful."There's attracting and tempting evidence out there that it will work,"he says.
If it does work in people,there might be good reasons for rejuvenating the liver. As we get older,our bodies are less efficient at metabolizing drugs,for example.A brief period of time of dieting,says Spindler,could be enough to make sure a. drug is effective.
But Spindler isn't sure the trade-off is worth it."The mice get less disease,they live longer,but they're hungry,"he says."Even seeing what a diet does,it's still hard to go to a restaurant and say:I can only eat half of that."
Spindler hopes we soon won't need to diet at all. His company,Lifespan Genetics in California, is looking for drugs that have the effects of calorie restriction.
第一篇
A meager（不足的）diet may give you health and long life, but it's not much fun一and it might not even be necessary. We may be able to hang on to most of that youthful（有青春活力的）vigor （精力）even if we don't start to diet until old age.
Stephen Spindler and his colleagues from the University of California at Riverside have found that some of an elderly mouse's liver genes can be made to behave as they did when the mouse was young simply by limiting its food for four weeks. The genetic rejuvenation（恢复活力，返老还童） won't reverse other damage caused by time for the mouse,but could help its liver metabolize（使进入新陈代谢过程）drugs or get rid of toxins.
Spindler's team fed three mice a normal diet for their whole lives,and fed another three on half-rations.Three more mice were switched from the normal diet to half-feed for a month when they were 34 months old一equivalent to about 70 human years.
The researchers checked the activity of 11,000 genes from the mouse livers,and found that 46 changed with age in the normally fed mice.The changes were associated with things like inflammation and free radical production一probably bad news for mouse health.In the mice that had dieted all their lives,27 of those 46 genes continued to behave like young genes.But the most surprising finding was that the mice that only started dieting in old age also benefited from 70 percent of these gene changes.
"This is the first indication that these effects kick in pretty quickly",says Huber Warner from the National Institute on Aging near Washington D.C.
No one yet knows if calorie restriction works in people as it does in mice,but Spindler is hopeful."There's attracting and tempting evidence out there that it will work,"he says.
If it does work in people,there might be good reasons for rejuvenating the liver. As we get older,our bodies are less efficient at metabolizing drugs,for example.A brief period of time of dieting,says Spindler,could be enough to make sure a. drug is effective.
But Spindler isn't sure the trade-off is worth it."The mice get less disease,they live longer,but they're hungry,"he says."Even seeing what a diet does,it's still hard to go to a restaurant and say:I can only eat half of that."
Spindler hopes we soon won't need to diet at all. His company,Lifespan Genetics in California, is looking for drugs that have the effects of calorie restriction.
Why does the author mention an elderly mouse in paragraph 2?
A:To describe the influence of old age on mice.
B:To illustrate the effect of meager food on mice.
C:To tell us how mice's liver genes behave.
D:To inform us of the process of metabolizing drugs.
A:To describe the influence of old age on mice.
B:To illustrate the effect of meager food on mice.
C:To tell us how mice's liver genes behave.
D:To inform us of the process of metabolizing drugs.
答案：B
解析：
第一段第一句讲“节食可能不是非做不可的事”，第二句讲“即使在年老以后才开始节食，我们也能保持大部分的青春活力”，因此，“我们必须从小就开始节食”是错误的，D是答案。
第二段提及“一只高龄老鼠”的时候，作者谈到，“只要连续四周限制一些衰老的老鼠进食，它们的肝脏基因就会变得和衰老前一样充满活力”。据此，“为了阐明节食对老鼠所产生的影响”最好地回答了题干中的问题。
第四段提到，“正常饲养的老鼠随着年龄的增长有46个肝脏基因会发生变化。这种变化与诸如炎症和体内自由基的产生有关”。因此D正确。
第四段最后一句讲“但最惊人的发现是那些上了年纪才开始节食的老鼠也能从70％的基因变化中受益”。“最惊人的”自然是“最令研究人员感兴趣的”。
文章的最后两段谈及Spindler对节食的看法。首先，他不能肯定节食是否值得；其次，他希望在不久的将来，我们不必节食。所以我们可以推知，他认为节食不是得以健康长寿的好办法。
第二段提及“一只高龄老鼠”的时候，作者谈到，“只要连续四周限制一些衰老的老鼠进食，它们的肝脏基因就会变得和衰老前一样充满活力”。据此，“为了阐明节食对老鼠所产生的影响”最好地回答了题干中的问题。
第四段提到，“正常饲养的老鼠随着年龄的增长有46个肝脏基因会发生变化。这种变化与诸如炎症和体内自由基的产生有关”。因此D正确。
第四段最后一句讲“但最惊人的发现是那些上了年纪才开始节食的老鼠也能从70％的基因变化中受益”。“最惊人的”自然是“最令研究人员感兴趣的”。
文章的最后两段谈及Spindler对节食的看法。首先，他不能肯定节食是否值得；其次，他希望在不久的将来，我们不必节食。所以我们可以推知，他认为节食不是得以健康长寿的好办法。
第10题：
共用题干
第二篇
Natural Medicines
Since earliest days,humans have used some kinds of medicines.We know this because humans have
survived.Ancient treatments for injury and disease were successful enough to keep humans from dying out
completely.
They were successful long before the time of modern medicine.Before the time of doctors with white
coats and shiny（发亮的）instruments. Before the time of big hospitals with strange and wonderful equipment.
Many parts of the world still do not have university-educated doctors. Nor do they have expensive hospi-
tals.Yet injuries are treated.And diseases are often cured.How?By ancient methods.By medicines that
might seem mysterious , even magical（有魔力的）.Traditional medicines are neither mysterious nor magical,
however.
Through the centuries, tribal（部族的）medicine men experimented with plants. They found many use-
ful chemicals in the plants.And scientists believe many of these traditional medicines may provide the cure
for some of today's most serious diseases.
Experts say almost 80% of the people in the world use plants for health care.These natural medicines
are used not just because people have no other form of treatment.They are used because people trust them.
In developed areas,few people think about the source of the medicines they buy in a store.Yet many wide-
ly-used medicines are from ancient sources,especially plants.Some experts say more than 25% of modern
medicines come,in one way or another,from nature.
Scientists have long known that nature is really a chemical factory.All living things contain chemicals
that help them survive.So scientists' interest in traditional medicine is not new.But it has become an ur-
gent concern.This is because the earth's supply of natural medicines may be dropping rapidly.
第二篇
Natural Medicines
Since earliest days,humans have used some kinds of medicines.We know this because humans have
survived.Ancient treatments for injury and disease were successful enough to keep humans from dying out
completely.
They were successful long before the time of modern medicine.Before the time of doctors with white
coats and shiny（发亮的）instruments. Before the time of big hospitals with strange and wonderful equipment.
Many parts of the world still do not have university-educated doctors. Nor do they have expensive hospi-
tals.Yet injuries are treated.And diseases are often cured.How?By ancient methods.By medicines that
might seem mysterious , even magical（有魔力的）.Traditional medicines are neither mysterious nor magical,
however.
Through the centuries, tribal（部族的）medicine men experimented with plants. They found many use-
ful chemicals in the plants.And scientists believe many of these traditional medicines may provide the cure
for some of today's most serious diseases.
Experts say almost 80% of the people in the world use plants for health care.These natural medicines
are used not just because people have no other form of treatment.They are used because people trust them.
In developed areas,few people think about the source of the medicines they buy in a store.Yet many wide-
ly-used medicines are from ancient sources,especially plants.Some experts say more than 25% of modern
medicines come,in one way or another,from nature.
Scientists have long known that nature is really a chemical factory.All living things contain chemicals
that help them survive.So scientists' interest in traditional medicine is not new.But it has become an ur-
gent concern.This is because the earth's supply of natural medicines may be dropping rapidly.
It can be seen from the passage that the earth's supply of natural medicines________.
A:may never be exhausted
B:may be dropping rapidly
C:is surprisingly big
D:is as rich as ever
A:may never be exhausted
B:may be dropping rapidly
C:is surprisingly big
D:is as rich as ever
答案：B
解析：
由文章第一段第二句话可知，古代的医疗手段已经足以让人类免于完全灭亡，即生存 下去。故选B。
由文章第三段可知，现在世界上的很多地方仍然没有高学历的医生，也没有治疗费昂贵的医院，但这些地方的人们仍有办法治疗疾病。他们仍然使用古老的医疗办法来治病。故 选A。
由文章第四段最后一句话可知，科学家们相信这些古老的医疗手段可能会给现今最严 重的疾病提供治愈方法。故选B。
由文章第五段第一句话可知，专家们说世界上80％的人们在用植物草药做医疗保健。 故选D。或者根据文章主题（文章标题Natural Medicine）直接选择答案。
由文章最后一段最后一句话，可知地球上的天然药物的供给量可能会急速下降。故 选B。第三篇 本篇文章主要讲述了人类为了改善生活使用技术工具改变了地球的自然面貌，在给自己带 来便利的同时却污染了环境，影响了生态平衡。
由文章第三段可知，现在世界上的很多地方仍然没有高学历的医生，也没有治疗费昂贵的医院，但这些地方的人们仍有办法治疗疾病。他们仍然使用古老的医疗办法来治病。故 选A。
由文章第四段最后一句话可知，科学家们相信这些古老的医疗手段可能会给现今最严 重的疾病提供治愈方法。故选B。
由文章第五段第一句话可知，专家们说世界上80％的人们在用植物草药做医疗保健。 故选D。或者根据文章主题（文章标题Natural Medicine）直接选择答案。
由文章最后一段最后一句话，可知地球上的天然药物的供给量可能会急速下降。故 选B。第三篇 本篇文章主要讲述了人类为了改善生活使用技术工具改变了地球的自然面貌，在给自己带 来便利的同时却污染了环境，影响了生态平衡。