专升本
Many countries are increasing their use of natural gas, wind and other forms of （）AenergyBsourceCpower Dmaterial
题目
Many countries are increasing their use of natural gas, wind and other forms of （）
Aenergy
Bsource
Cpower
Dmaterial
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相似问题和答案
第1题：
The total cost in logistics in China is still higher than()in many other industrialized countries.
A、it
B、that
C、those
参考答案：B
第2题：
Many countries are increasing their use of natural gas, wind, and other forms of ( ).
A、source
B、material
C、power
D、energy
参考答案：D
第3题：
Hepatitis A vaccines are especially recommended for those who ()
A、travel abroad
B、have other forms of liver disease
C、have many sexual partners
D、are in high-risk occupations
参考答案：ABCD
第4题：
共用题干
Energy and Public Lands
The United States boasts substantial energy resources. Federal lands provide a good deal of US energy production,the US Department of the Interior manages federal energy leasing （租赁）both on land and on the offshore Outer Continental Shelf Production from these sources amounts to nearly 30 percent of total annual US energy production.
In 2000,32 percent of US oil,35 percent of natural gas,and 37 percent of coal were pro-duced from federal lands,representing 20,000 producing oil and gas leases and 135 producing coal leases. Federal lands are also estimated to contain approximately 68 percent of all undis-covered US oil reserves and 74 percent of undiscovered natural gas.
Revenues from federal oil,gas,and coal leasing provide significant returns to US taxpayers as well as State Government. In 1999,for example,$553 million in oil and gas revenues were paid to the US Treasury,and non-India coal leases accounted for over$304 million in revenues,of which 50 percent were paid to State governments. Public lands also play a critical role in energy delivery. Each year , federal land managers authorize（许可）rights of way for transmission lines , rail systems , pipe-lines,and other facilities related to energy production and use.
Alternative energy production from federal lands falls behind conventional energy pro-duction , though the amount is still significant. For example , federal geothermal（地热）re-sources produce about 7. 5 billion kilowatt-hours（千瓦时）of electricity per year,47 percent of all electricity generated from US geothermal energy. There are 2,960 wind turbines on public lands in California alone,producing electricity for about 300,000 people. Federal hydropower （水电）facilities produce about 17 percent of all hydropower produced in the United States.
Because of the growing US thirst for energy and increasing public unease with depend-ence on foreign off sources,pressure on public lands to meet US energy demand is becoming more intense. Public lands are available for energy development only after they have been evaluated through the land use planning process.If development of energy resources conflicts with management or use of other resources,development restrictions or impact moderation measures may be enforced,or mineral be banned altogether.
Energy and Public Lands
The United States boasts substantial energy resources. Federal lands provide a good deal of US energy production,the US Department of the Interior manages federal energy leasing （租赁）both on land and on the offshore Outer Continental Shelf Production from these sources amounts to nearly 30 percent of total annual US energy production.
In 2000,32 percent of US oil,35 percent of natural gas,and 37 percent of coal were pro-duced from federal lands,representing 20,000 producing oil and gas leases and 135 producing coal leases. Federal lands are also estimated to contain approximately 68 percent of all undis-covered US oil reserves and 74 percent of undiscovered natural gas.
Revenues from federal oil,gas,and coal leasing provide significant returns to US taxpayers as well as State Government. In 1999,for example,$553 million in oil and gas revenues were paid to the US Treasury,and non-India coal leases accounted for over$304 million in revenues,of which 50 percent were paid to State governments. Public lands also play a critical role in energy delivery. Each year , federal land managers authorize（许可）rights of way for transmission lines , rail systems , pipe-lines,and other facilities related to energy production and use.
Alternative energy production from federal lands falls behind conventional energy pro-duction , though the amount is still significant. For example , federal geothermal（地热）re-sources produce about 7. 5 billion kilowatt-hours（千瓦时）of electricity per year,47 percent of all electricity generated from US geothermal energy. There are 2,960 wind turbines on public lands in California alone,producing electricity for about 300,000 people. Federal hydropower （水电）facilities produce about 17 percent of all hydropower produced in the United States.
Because of the growing US thirst for energy and increasing public unease with depend-ence on foreign off sources,pressure on public lands to meet US energy demand is becoming more intense. Public lands are available for energy development only after they have been evaluated through the land use planning process.If development of energy resources conflicts with management or use of other resources,development restrictions or impact moderation measures may be enforced,or mineral be banned altogether.
There is a mounting pressure on public lands to satisfy US energy demands because______.
A: many Americans are unhappy with energy development in foreign countries
B: the U. S. is demanding more and more energy
C: quite a few public lands are banned for energy development
D: many Americans think public lands are being abused
A: many Americans are unhappy with energy development in foreign countries
B: the U. S. is demanding more and more energy
C: quite a few public lands are banned for energy development
D: many Americans think public lands are being abused
答案：B
解析：
题干意为“这篇短文的主旨是什么？公共土地在能源生产方面发挥了重要作用。”短文第一段第二句提到“联邦土地为美国的能源生产提供了大量资源”，下文分别介绍了公共土地提供传统能源和替代能源的情况，故选C。
题干意为“关于美国的公共土地，下列哪一项叙述是真实的？大部分未开发的天然气存储在那里。”短文第二段最后一句提到“据估计，联邦土地中蕴含美国未开发天然气资源的74 %”，故选D。
题干意为“第四段中提到的地热资源，风力涡轮机和水力发电设备作为例子是用来证明 来自公共土地的替代能源资源数量非常大。”短文第四段第一句提到“联邦土地的替代能源生产要落后于传统能源生产，尽管前者的数量也非常巨大”，下文用几个数字表明替代资源的客观数量：地热资源每年生产75亿千瓦时的电力，仅加利福尼亚的公共土地上就有 2960个风力涡轮机等，水电生产占全美国水电生产的17%。故选D。
题干意为“公共土地在满足美国能源需要方面的压力不断增加，因为 美国需要越来越多的能源。”短文第五段第一句提到美国对能源的渴求不断增长，而且公众对于依靠进口资源这种状况感到不安，所以公共土地在满足美国能源需求方面的压力越来越大。故选B。
题干意为“当公共土地通过土地利用规划程序 时它们才可以用于能源开发。”短文最后一段第二句提到“公共土地只有通过了土地利用规划程序才可以用来开发能源”，故选A。
题干意为“关于美国的公共土地，下列哪一项叙述是真实的？大部分未开发的天然气存储在那里。”短文第二段最后一句提到“据估计，联邦土地中蕴含美国未开发天然气资源的74 %”，故选D。
题干意为“第四段中提到的地热资源，风力涡轮机和水力发电设备作为例子是用来证明 来自公共土地的替代能源资源数量非常大。”短文第四段第一句提到“联邦土地的替代能源生产要落后于传统能源生产，尽管前者的数量也非常巨大”，下文用几个数字表明替代资源的客观数量：地热资源每年生产75亿千瓦时的电力，仅加利福尼亚的公共土地上就有 2960个风力涡轮机等，水电生产占全美国水电生产的17%。故选D。
题干意为“公共土地在满足美国能源需要方面的压力不断增加，因为 美国需要越来越多的能源。”短文第五段第一句提到美国对能源的渴求不断增长，而且公众对于依靠进口资源这种状况感到不安，所以公共土地在满足美国能源需求方面的压力越来越大。故选B。
题干意为“当公共土地通过土地利用规划程序 时它们才可以用于能源开发。”短文最后一段第二句提到“公共土地只有通过了土地利用规划程序才可以用来开发能源”，故选A。
第5题：
共用题干
If you made a list of all the jobs performed by the different kinds of energy,you would fill many pages.
Nuclear energy is used in some areas of the United States.But there are dangers.Waste materials from nuclear______(51)would destroy life if they leaked______(52)the land.When nuclear energy is produced,a lot of______(53)is produced,too,50 a flow of lake or ocean water 15 used to cool the operations.Then the water______(54)to its source.If the returning water were too hot,it would destroy fish and other______(55).
Cow manure is being used to produce a kind of______(56).The manure from farms is put into a machine to convert it to a liquid.Then the gas 15 formed______(57)a natural process.If the converter were not 50______(58)at the present time,it would be used in many places to provide______(59).
Garbage has become an energy source.It______(60)to oil,steam,or electricity,or it is used on the land.
But recent______(61)about power supplies has led to increased interest in the use of wind______(62)a source of electrical power.Windmills are clean and they______(63)no waste.And they use a______(64)resource.Some scientists consider that wind energy systems can fulfill a valuable______(65)in meeting the energy needs of industrialized nations and of the developing world.
If you made a list of all the jobs performed by the different kinds of energy,you would fill many pages.
Nuclear energy is used in some areas of the United States.But there are dangers.Waste materials from nuclear______(51)would destroy life if they leaked______(52)the land.When nuclear energy is produced,a lot of______(53)is produced,too,50 a flow of lake or ocean water 15 used to cool the operations.Then the water______(54)to its source.If the returning water were too hot,it would destroy fish and other______(55).
Cow manure is being used to produce a kind of______(56).The manure from farms is put into a machine to convert it to a liquid.Then the gas 15 formed______(57)a natural process.If the converter were not 50______(58)at the present time,it would be used in many places to provide______(59).
Garbage has become an energy source.It______(60)to oil,steam,or electricity,or it is used on the land.
But recent______(61)about power supplies has led to increased interest in the use of wind______(62)a source of electrical power.Windmills are clean and they______(63)no waste.And they use a______(64)resource.Some scientists consider that wind energy systems can fulfill a valuable______(65)in meeting the energy needs of industrialized nations and of the developing world.
_________(61)
A:consideration
B:thought
C:concern
D:interest
A:consideration
B:thought
C:concern
D:interest
答案：C
解析：
station“站”;factory“工厂”;work“工厂”;firm“公司”。根据下文内容，这里应该是“核电站”，因此选A。
into“进入……”;onto“在……表面”;on“在……上”;to“去……”。根据下文内容，这里应该是“从核电站里排放的废气物质如果遗漏在地面上”，因此选B。
high temperature“高j" ;hot air“热气”;heat“热量”;warmth"温暖”。本句意思是：“产生核能的同时会产生大量热能”。因此选C。
get“得到”;come“来”;fall“落下”;return“返回”，最符合题意。本句意思是：“水会随后流回”。因此选D。
根据常识，海洋里有生命的不止是动物或者植物，而是所有有生命的生物。本句意思是：“如果流回的水太热就会杀死鱼类和其他海里的生命”。因此选C。
gas“天然气”;liquid“液体”;solid“固体”; air“空气”。根据下文，本句意思是：“牛粪被用来生产一种天然气”。因此选A。
by“被…." ;through“通过……方式”;with“与……一起”;from“从……”。本句意思是：“通过自然过程形成天然气”。若用by会有be formed by结构中“构成”的被动式的竣义，因此选B。
expensive"昂贵的”;complicated“复杂的”;rare"稀少的”;troublesome"麻烦的”。本句意思是：“如果目前转换器不昂贵，就能被广泛用来提供能源”。因此选A。
oil“油”;liquid“液体”;power“电力”;fuel“能源”。此处需要的内容是指能源总称，而不是具体的一类能源，因此选D。
此处的意思是“被转换成……”，正确的形式是be converted to...。本句意思是：“它能被转变为油、蒸汽或电，在农村也有用途”。因此选D。
consideration“考虑”;thought“想法”;concern“关心的事”;interest“兴趣”。根据上下文此处应指对能源的关注，因此选C。
like“像……”;as“作为……”;for“为……”;from“从……”。根据本句意思，应选B。
give“给”;deposit“存放”;make“制作”;leave“留下”。本句意思是：“没有遗留污染物”。因此选D。
measureless“不可坝d量的”; limitless“无限的”; boundless“无边无际的”; endless“没完没了的”。此处的意思是：“风力发电有无限的能量来源”。因此选B。
role“角色”; duty“职责”; service“服务”; function“功能”。本句意思是： “一些科学家认为风能在满足工业国家和发展中国家的能源需求方面扮演着很有价值的角色”。因此选A。
into“进入……”;onto“在……表面”;on“在……上”;to“去……”。根据下文内容，这里应该是“从核电站里排放的废气物质如果遗漏在地面上”，因此选B。
high temperature“高j" ;hot air“热气”;heat“热量”;warmth"温暖”。本句意思是：“产生核能的同时会产生大量热能”。因此选C。
get“得到”;come“来”;fall“落下”;return“返回”，最符合题意。本句意思是：“水会随后流回”。因此选D。
根据常识，海洋里有生命的不止是动物或者植物，而是所有有生命的生物。本句意思是：“如果流回的水太热就会杀死鱼类和其他海里的生命”。因此选C。
gas“天然气”;liquid“液体”;solid“固体”; air“空气”。根据下文，本句意思是：“牛粪被用来生产一种天然气”。因此选A。
by“被…." ;through“通过……方式”;with“与……一起”;from“从……”。本句意思是：“通过自然过程形成天然气”。若用by会有be formed by结构中“构成”的被动式的竣义，因此选B。
expensive"昂贵的”;complicated“复杂的”;rare"稀少的”;troublesome"麻烦的”。本句意思是：“如果目前转换器不昂贵，就能被广泛用来提供能源”。因此选A。
oil“油”;liquid“液体”;power“电力”;fuel“能源”。此处需要的内容是指能源总称，而不是具体的一类能源，因此选D。
此处的意思是“被转换成……”，正确的形式是be converted to...。本句意思是：“它能被转变为油、蒸汽或电，在农村也有用途”。因此选D。
consideration“考虑”;thought“想法”;concern“关心的事”;interest“兴趣”。根据上下文此处应指对能源的关注，因此选C。
like“像……”;as“作为……”;for“为……”;from“从……”。根据本句意思，应选B。
give“给”;deposit“存放”;make“制作”;leave“留下”。本句意思是：“没有遗留污染物”。因此选D。
measureless“不可坝d量的”; limitless“无限的”; boundless“无边无际的”; endless“没完没了的”。此处的意思是：“风力发电有无限的能量来源”。因此选B。
role“角色”; duty“职责”; service“服务”; function“功能”。本句意思是： “一些科学家认为风能在满足工业国家和发展中国家的能源需求方面扮演着很有价值的角色”。因此选A。
第6题：
In Britain and many other countries appraisal is now a tool of management.
A．evaluation
B．efficiency
C．production
D．publicity
正确答案：A
解析：本题考查的是对动词的认知。这句话的意思是：在英国和其他很多国家，个人评定现在成为了一种管理工具。本题中appraisal本意为“估计、评价”。在管理中指员工鉴定、个人评价。A．evaluation评价；B．efficiency效率；C．production生产；D．publicity出名。选A：evaluation，例如：Evaluation is standard practice for all training．评价是各种教育通常的做法。
解析：本题考查的是对动词的认知。这句话的意思是：在英国和其他很多国家，个人评定现在成为了一种管理工具。本题中appraisal本意为“估计、评价”。在管理中指员工鉴定、个人评价。A．evaluation评价；B．efficiency效率；C．production生产；D．publicity出名。选A：evaluation，例如：Evaluation is standard practice for all training．评价是各种教育通常的做法。
第7题：
The tradition of using chopsticks was introduced ______ many other countries.
A、with
B、of
C、from
D、to
参考答案：D
第8题：
We also use other forms of communication () we may be aware or unaware.
A、to which
B、of which
C、which
D、that
参考答案：B
第9题：
共用题干
Natural Gas
1 Natural gas is produced from reservoirs deep beneath the earth's surface. It is a fossil fuel（矿物燃
料）,meaning that it is derived from organic material buried in the earth millions of years ago.The main corn-
ponent of natural gas is methane（甲烷）.
2 The popularity and use of clean natural gas have increased dramatically over the past 50 years as
pipeline infrastructure（基础设施）has been installed to deliver it conveniently and economically to millions
of residential,commercial and industrial customers worldwide.Today,natural gas service is available in all 50
states in the U.S.,and is the leading energy choice for fueling American homes and industries.More than 65
million American homes use natural gas.In fact,natural gas is the most economical source for home energy
needs,costing one-third as much as electricity. In addition to heating homes,much of the gas used in the United
States is used as a raw material to manufacture a wide variety of products,from paint,to fibers for clothing,to
plastics for healthcare,computing and furnishings.Natural gas is also used in a significant number of new
electricity-generating power plants.
3 Natural gas is one of the safest and cleanest fuels available. It emits（发出）less pollution than other
fossil fuels sources. When natural gas is burned,it produces mostly carbon dioxide（二氧化碳）and water va-
por一the same substances emitted when humans breathe.Compared with some other fossil fuels,natural gas
emits the least amount of carbon dioxide into the air when combusted（燃烧）一making natural gas the clea--
nest burning fossil fuel of all.
4 The United States consumes about one-third of the world's natural gas output,making it the largest
gas-consuming region in the world.The U.S.Department of Energy Information Administration forecasts that
natural gas demand will grow by more than 50 percent by 2025.
5 There are huge reserves of natural gas beneath the earth's surface.The largest reserves of natural
gas can be found in Russia , West and North Africa and the Middle East. LNG（液化天然气）has been pro-
duced domestically and imported in the United States for more than four decades.Today,the leading import-
ers of LNG are Japan,Korea,France and Spain.
Natural Gas
1 Natural gas is produced from reservoirs deep beneath the earth's surface. It is a fossil fuel（矿物燃
料）,meaning that it is derived from organic material buried in the earth millions of years ago.The main corn-
ponent of natural gas is methane（甲烷）.
2 The popularity and use of clean natural gas have increased dramatically over the past 50 years as
pipeline infrastructure（基础设施）has been installed to deliver it conveniently and economically to millions
of residential,commercial and industrial customers worldwide.Today,natural gas service is available in all 50
states in the U.S.,and is the leading energy choice for fueling American homes and industries.More than 65
million American homes use natural gas.In fact,natural gas is the most economical source for home energy
needs,costing one-third as much as electricity. In addition to heating homes,much of the gas used in the United
States is used as a raw material to manufacture a wide variety of products,from paint,to fibers for clothing,to
plastics for healthcare,computing and furnishings.Natural gas is also used in a significant number of new
electricity-generating power plants.
3 Natural gas is one of the safest and cleanest fuels available. It emits（发出）less pollution than other
fossil fuels sources. When natural gas is burned,it produces mostly carbon dioxide（二氧化碳）and water va-
por一the same substances emitted when humans breathe.Compared with some other fossil fuels,natural gas
emits the least amount of carbon dioxide into the air when combusted（燃烧）一making natural gas the clea--
nest burning fossil fuel of all.
4 The United States consumes about one-third of the world's natural gas output,making it the largest
gas-consuming region in the world.The U.S.Department of Energy Information Administration forecasts that
natural gas demand will grow by more than 50 percent by 2025.
5 There are huge reserves of natural gas beneath the earth's surface.The largest reserves of natural
gas can be found in Russia , West and North Africa and the Middle East. LNG（液化天然气）has been pro-
duced domestically and imported in the United States for more than four decades.Today,the leading import-
ers of LNG are Japan,Korea,France and Spain.
Natural gas is recognized as the most economical energy source______________.
A:over the past 50 years
B:beneath the earth's surface
C:by more than 50 percent
D:for more than four decades
E:as a raw material
F:for home energy needs
A:over the past 50 years
B:beneath the earth's surface
C:by more than 50 percent
D:for more than four decades
E:as a raw material
F:for home energy needs
答案：F
解析：
本段的中心意思是天然气被广泛应用以及天然气的各种用途。
本段的中心意思是天然气是现有能源中极安全、极干净的一种。
本段的中心意思是美国消费天然气的情况。
本段的中心意思是世界上天然气的储存和供应情况。
根据第一段的第一句话可知答案。
根据第二段的第四句话可知答案。
根据第二段的第五句话可知答案。
根据第四段的最后一句话可知答案。第4部分：阅读理解第一篇 本文介绍了一项研究，该研究显示步行能健脑，经常运动可以使老年人更好地集中精力。
本段的中心意思是天然气是现有能源中极安全、极干净的一种。
本段的中心意思是美国消费天然气的情况。
本段的中心意思是世界上天然气的储存和供应情况。
根据第一段的第一句话可知答案。
根据第二段的第四句话可知答案。
根据第二段的第五句话可知答案。
根据第四段的最后一句话可知答案。第4部分：阅读理解第一篇 本文介绍了一项研究，该研究显示步行能健脑，经常运动可以使老年人更好地集中精力。
第10题：
共用题干
Natural Gas
1 Natural gas is produced from reservoirs deep beneath the earth's surface. It is a fossil fuel（矿物燃
料）,meaning that it is derived from organic material buried in the earth millions of years ago.The main corn-
ponent of natural gas is methane（甲烷）.
2 The popularity and use of clean natural gas have increased dramatically over the past 50 years as
pipeline infrastructure（基础设施）has been installed to deliver it conveniently and economically to millions
of residential,commercial and industrial customers worldwide.Today,natural gas service is available in all 50
states in the U.S.,and is the leading energy choice for fueling American homes and industries.More than 65
million American homes use natural gas.In fact,natural gas is the most economical source for home energy
needs,costing one-third as much as electricity. In addition to heating homes,much of the gas used in the United
States is used as a raw material to manufacture a wide variety of products,from paint,to fibers for clothing,to
plastics for healthcare,computing and furnishings.Natural gas is also used in a significant number of new
electricity-generating power plants.
3 Natural gas is one of the safest and cleanest fuels available. It emits（发出）less pollution than other
fossil fuels sources. When natural gas is burned,it produces mostly carbon dioxide（二氧化碳）and water va-
por一the same substances emitted when humans breathe.Compared with some other fossil fuels,natural gas
emits the least amount of carbon dioxide into the air when combusted（燃烧）一making natural gas the clea--
nest burning fossil fuel of all.
4 The United States consumes about one-third of the world's natural gas output,making it the largest
gas-consuming region in the world.The U.S.Department of Energy Information Administration forecasts that
natural gas demand will grow by more than 50 percent by 2025.
5 There are huge reserves of natural gas beneath the earth's surface.The largest reserves of natural
gas can be found in Russia , West and North Africa and the Middle East. LNG（液化天然气）has been pro-
duced domestically and imported in the United States for more than four decades.Today,the leading import-
ers of LNG are Japan,Korea,France and Spain.
Natural Gas
1 Natural gas is produced from reservoirs deep beneath the earth's surface. It is a fossil fuel（矿物燃
料）,meaning that it is derived from organic material buried in the earth millions of years ago.The main corn-
ponent of natural gas is methane（甲烷）.
2 The popularity and use of clean natural gas have increased dramatically over the past 50 years as
pipeline infrastructure（基础设施）has been installed to deliver it conveniently and economically to millions
of residential,commercial and industrial customers worldwide.Today,natural gas service is available in all 50
states in the U.S.,and is the leading energy choice for fueling American homes and industries.More than 65
million American homes use natural gas.In fact,natural gas is the most economical source for home energy
needs,costing one-third as much as electricity. In addition to heating homes,much of the gas used in the United
States is used as a raw material to manufacture a wide variety of products,from paint,to fibers for clothing,to
plastics for healthcare,computing and furnishings.Natural gas is also used in a significant number of new
electricity-generating power plants.
3 Natural gas is one of the safest and cleanest fuels available. It emits（发出）less pollution than other
fossil fuels sources. When natural gas is burned,it produces mostly carbon dioxide（二氧化碳）and water va-
por一the same substances emitted when humans breathe.Compared with some other fossil fuels,natural gas
emits the least amount of carbon dioxide into the air when combusted（燃烧）一making natural gas the clea--
nest burning fossil fuel of all.
4 The United States consumes about one-third of the world's natural gas output,making it the largest
gas-consuming region in the world.The U.S.Department of Energy Information Administration forecasts that
natural gas demand will grow by more than 50 percent by 2025.
5 There are huge reserves of natural gas beneath the earth's surface.The largest reserves of natural
gas can be found in Russia , West and North Africa and the Middle East. LNG（液化天然气）has been pro-
duced domestically and imported in the United States for more than four decades.Today,the leading import-
ers of LNG are Japan,Korea,France and Spain.
Paragraph 4 ______________
A:Popularity and Use of Natural Gas
B:Natural Gas Reserves and Supply
C:Natural Gas Prices
D:Clean Fuel of Choice
E:Disadvantages of Natural Gas
F:Natural Gas Consumption
A:Popularity and Use of Natural Gas
B:Natural Gas Reserves and Supply
C:Natural Gas Prices
D:Clean Fuel of Choice
E:Disadvantages of Natural Gas
F:Natural Gas Consumption
答案：F
解析：
本段的中心意思是天然气被广泛应用以及天然气的各种用途。
本段的中心意思是天然气是现有能源中极安全、极干净的一种。
本段的中心意思是美国消费天然气的情况。
本段的中心意思是世界上天然气的储存和供应情况。
根据第一段的第一句话可知答案。
根据第二段的第四句话可知答案。
根据第二段的第五句话可知答案。
根据第四段的最后一句话可知答案。第4部分：阅读理解第一篇 本文介绍了一项研究，该研究显示步行能健脑，经常运动可以使老年人更好地集中精力。
本段的中心意思是天然气是现有能源中极安全、极干净的一种。
本段的中心意思是美国消费天然气的情况。
本段的中心意思是世界上天然气的储存和供应情况。
根据第一段的第一句话可知答案。
根据第二段的第四句话可知答案。
根据第二段的第五句话可知答案。
根据第四段的最后一句话可知答案。第4部分：阅读理解第一篇 本文介绍了一项研究，该研究显示步行能健脑，经常运动可以使老年人更好地集中精力。