问题 名词解释

自行

答案

参考答案:

自行,恒星在一年内沿垂直于观测者视线方向走过的距离对观测者所张的角度。天上的星星看上去是不动的,年复一年我们总在一定的时间里能见到它们。但是,如果我们用天文望远镜去精细地测量它们的位置,并与过去得到的结果相比较,就会发现它们的位置是不一样的,这是由于自行的结果。

星星的自行一般都很小。要比较相隔几十年的观测结果才能求得,而且星星距离我们愈远,自行愈小。但是,到目前为止,也发现了少数自行值大的星星。其中有400多颗星的自行每年等于或大于1角秒,有50颗星的自行每年大于2角秒。

阅读理解

阅读理解。

     In the United States, headmasters and teachers disci?pline (惩罚) students in several ways. The teacher often writes to or calls the students' parents. Sometimes students have to stay at school for one hour. If a

student behaves very badly, the headmaster can stop the student having classes. The student can't come to school for one, two or three days. Mr Lazares, the headmaster of a middle school in Ohio, did not like to do so. When he didn't  let the students come to  school,  they were happy.  "A  three-day holiday!"  They

thought

     One day,  a boy was in  Mr  Lazares's office.  The boy was not  behaving  well in class.  Mr Lazares

telephoned the boy's parents. "If you come to school with your son, I won't stop him having classes, " he

said. The boy's father came to school and went with his son to every class.  Other students looked at the

boy and his father. The boy was em ?barrassed (难为情).  After that he behaved better. And, of course,

other students behaved better, too.

     Now headmasters all over the USA are trying Mr Lazares's idea. They, too, think that students behave better when parents come to school.

1. What does a headmaster usually do to the student if he behaves very badly?

A. Writes to the student's parents.    

B. Lets the student stay at school for an hour.

C. Calls the student's parents.  

D.Stops the student  havirig  classes  for  several days.

2. When a student having classes for several days, he was______.

A. happy    

B. angry  

C. worried    

D. afraid

3. What' did Mr Lazares do when his students were not behaving well in class?

A. Tried to talk to them.            

B. Sent them home.

C. Telephoned their parents to come to school and go to classes with them.    

D. Had them stay in his office.

4. Why did the other students behave better, too?

A. They didn't like to have clasfes with the boy's father.

B. They didn't want  their parents  to come to school.

C. They were afraid of teachers.    

D. They were afraid of Mr Lazarfe.

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