海船船员考试
单选题For many years marine centrifuges were designed for （） operation, that is the machines were run for a period during which solids accumulated in the bowlThe machine was stopped when the accumulated solids began to impair its performance.A purifyingB bat
题目
purifying
batch
long period
temporary
参考答案和解析
相似问题和答案
第1题：
People tend to talk about presents in a fairly loving way. A woman whose mother had died years ago described the many gifts around her house.These were gifts that her mother had given her over the years:“I appreciate these, and they mean something to me,”the woman said,“because I remember the occasions they were given on, and that they were from my mother, and the relationship we’ve had.”The gifts remain and keep the relationship alive in mind. This woman felt the same way about the gifts she gave to others. She hoped that the recipients would look at here gifts in years to come and
第2题：
Sydney Opera House will outlive the Guggenheim as an international architectural icon ______.
A．because it is a global expression of cultural modernity
B．because it is the first designed and built modern building
C．because everyone in the world with media access knows what the Sydney Opera House looks like
D．because it is the pioneer in accomplishing such an international architectural icon
解析：细节题。由题干outlive the Guggenheim定位到第二段末句，这里说到悉尼剧院将比古根海姆博物馆更加流传，因为它是国际建筑的开路先锋，D“因为它是现代国际性建筑偶像的鼻祖”与此意一致。A尽管在文章中提到了，但不算是题干中提到的原因：B中的first有问题，第二段尽管提到the opera house was the single best-known modern building，但并没有说是第一；C只是在陈述悉尼歌剧院闻名的程度。
第3题：
根据下列材料请回答 26～30 题：
B
Today there are policemen everywhere, but in 1700, London had no policemen at all. A few old men used to protect the city streets at night and they were not paid.
About 300 years ago, London was starting to get bigger and more and more people began to live there. The city was very dirty and many people were poor. There were so many thieves who stole money in the streets that people stayed in their homes as much as possible.
In 1750, Henry Fielding started to pay a group of people to stop thieves. They were like policemen and were called "Bow Street Runners" because they worked near Bow Street.
Fifty years later, there were 120 "Bow Street Runners", but London had become very big and needed more policemen. So in 1829, the first Metropolitan (or London)Police Force was started with 3,000 officers. Most of the men worked on foot, but a few rode horses. Until 1920 all the police in London were men.
Today. the London police are quite well paid and for the few police officers who still ride horses, the pay is even better than for the others.
第 26 题 In 1700, the men who protected the streets were paid __________.
A． a few
B． nothing
C． a little
D． a lot
根据第一段最后中的they were not paid可以知道他们没有任何报酬，所以答案选B。
第4题：
She()close contacts with the scientist for many years.
A、 maintained
B、 stayed
C、 claimed
第5题：
Many Mayan cities and temples__________ .
A． were constructed by the priests
B． were built with heavy stones
C． were rebuilt several times
D． were the miracles of god
细节推断题。文章第二段第四旬提到“because they had no horses to carry the heavy stones they used to build with”(因为他们没有马匹来拖运沉重的石材)，由此可知B项正确。
第6题：
There were many pictures on the wall．（改为一般疑问句）
________,________many pictures on the wall?
44. Were there
第7题：
The design of the Sydney Opera House has been taken as a myth because ______.
A．it was the workpiece of the famous architect
B．it met most of the rules for architectural design at that time
C．the design project suggested by Utzon was unbuildable
D．it was designed by an unknown architect and was thought unbuildable at that time
解析：细节题。由题干myth定位到第三段第二句，这里指出悉尼歌剧院成为神话的原因为the unknown architect，ignored most of the rules以及the design was unbuildable。D是对第一个和第三个原因的总结，为正确答案。A中的famous architect与原文unknown architect不符；B中的meet与原文中的ignore冲突；C只是片面说法。
第8题：
How many people were there in Anna's family?
________________________.
Five.
第9题：
22． What kind of movies do many young people like?
A． Thrillers
B． Action movies
C． Cartoon movies
D． Beijing Opera
22．B【解析】第四句及第六句可说明这一点。
第10题：
Not only() many cars built in the 1970s ugly and poorly designed, they also became very unreliable after 4050 thousand miles.
A. was
B. are
C. were