问题 名词解释

反应性ρ reactivity

答案

参考答案:表征链式核裂变反应介质或系统偏离临界程度的一个参数,定量地表示为反应性ρ为正值相应于超临界状态,负值相应于次临界状态,反应性ρ为零相应于临界状态。

判断题
阅读理解

阅读理解。

     Hello, I am Tom Green.  I am from  the USA.  Dick White is our teacher.  He is from England. He

teaches us English. He teaches well. Hi's classes are very interesting. Mr White is good with us, but he

is also very strict with us.

     Mr White has three kids. Mona and Lucy are his daughters. And Bill is his son.  Mona is nine years

old. Bill is seven years old. Lucy is  only  one year old.  Mona and  Bill go to school.  But Lucy doesn't.

Hergrandmother looks after her at home.

     Mr White likes to wear a T-shirt and jeans. He likes sports.  His favorite sport is basketball. After

school we usually have a soccer match.  Sometimes(有时)  Mr Green watches us play and sometimes

he joins us.  He plays soccer just for fun.

1. Tom Green is __________.  

A. a Chinese student        

B. an English student

C. an American teacher      

D. an American student

2.How may sons does Mr White have?

A.One          

B. Two.        

C.Three            

D. Sorry, I don't know.

3.Lucy  doesn't go to school because __________       

A.she is too young(小)

B. she doesn't like to go to school

C. her father doesn't like her to go to school

D.  she thinks school is too difficult

4. __________is  Mr White's favorite sport.

A. Soccer    

B. Baseball  

C. Tennis  

D. Basketball

5. Which of the following is RIGHT?    

A. Mr White doesn't like his students.

B. Mr White is not strict with his students.

C. Mr White plays basketball just for fun.

D. Sometimes Mr White joins his students in their soccer ball matches.