问题 单项选择题

设备安装精度测量时,下列误差中,属于形状误差的是()。

A.垂直度

B.同轴度

C.倾斜度

D.圆柱度

答案

参考答案:D

解析:形状误差是指被测实际要素对其理想要素的变动量,而位置误差则是关联实际要素的位置对基准的变动全量。从两者概念出发分析,A、B、C,三项均是相对于基准的变动量,而圆柱度则符合形状误差概念的描述。故选D。

阅读理解

阅读理解

     Most people have jobs. They go to work nearly every day. Some people are lucky. Either they have very

interesting jobs or they make a lot of money. Most people are not so lucky. Either their jobs are not very

interesting or they don't make a lot of money.

     The most interesting jobs are often the most difficult. People take a long time to learn how to do them.

Doctors study for at least(至少) six years after finishing school. Airline pilots(航天飞行员) study longer.

Most airline pilots are at least 30 years old.

     Some young people have interesting and well-paid(高收入) jobs. Many successful stars are usually under

35. Older people usually cannot play these sports very well. They cannot move fast enough(足够的). Golf,

however, is good sport for older people. Many successful golfers are quite old.

     Most people work until(直到) they are 60 or 65 years old. Then they retire(退休) and have a lot of free time.

Some people never (从不) retire. These people usually have very interesting jobs. Writers, artists, musicians

and actors usually work until they die. Their work is their life.

1.What kind of jobs do lucky people have?

A. Easy jobs with less(很少) money.

B. Not very interesting jobs.

C. Interesting and good jobs with much money.

D. Difficult jobs with less money

2.Why do some jobs take a long time to learn?

A. Because they are difficult.

B. Because they are well-paid

C. Because they are interesting.

D. Because they are easy.

3. Why are young people successful at sports like tennis?

A. Because they can move fast.

B. Because they don't have to study.

C. Because they get paid a lot of money.

D. Because they can't move fast.

4. Who has to(不得不) retire when he is 60?

A. A writer   B. An actor   C.  A policeman     D.  A musician

5. What does the word "die"mean in Chinese?

A. 喜欢

B. 死亡

C. 想

D. 生病

单项选择题