问题 配伍题 B型题

根据《电离辐射防护与辐射源安全基本标准》(GB18871-2002),用于公众的5年平均剂量限值(有效剂量)为() |根据《电离辐射防护与辐射源安全基本标准》(GB18871-2002),用于职业照射的年剂量限值(有效剂量),任何单独一年不超过()

A.1mSv

B.20mSv

C.50mSv

D.15mSv

E.500mSv

答案

参考答案:A|C

解析:1.根据《电离辐射防护与辐射源安全基本标准》(GB18871-2002),实践使公众中有关关键人群组的成员所受到的平均剂量估计值不应超过下述限值:①年有效剂量1mSv;②特殊情况下,如果5个连续年的年平均剂量不超过1mSv,则某一单一年份的有效剂量可提高到5mSv。2.根据《电离辐射防护与辐射源安全基本标准》(GB18871-2002),应对任何工作人员的职业照射水平进行控制,使之不超过下述限值:①由审管部门决定的连续5年的年平均有效剂量(但不可作任何追溯性平均)20mSv;②任何一年中的有效剂量50mSv。

单项选择题
阅读理解

阅读理解。

      Parents whose children show a special interest in a sport feel very difficult to make a decision about their

children's careers. Should they allow their children to train to become top sports men and women? For many

children it means starting schoolwork very young, and going out with friends and other interests have to take

a second place. It's very difficult to explain to a young child why he or she has to train five hours a day, even

at the weekend, when most of his or her friends are playing.

      Another problem is of course money. In many countries money for training is available from government

for the very best young sportsmen and women. If this help can not be given, it means that it is the parents

who have to find the time and the money to support their child's development and sports clothes, transport to

competitions, special equipment, etc. Can all be very expensive?

      Many parents are worried that it is dangerous to start serious training in a sport at an early age. Some

doctors agree that young muscles may be damaged by training before they are properly developed. Professional

(专业的) trainers, however, believe that it is only by training young that you can reach the top as a successful

sports person. It is clear that very few people do reach the top, and both parents and children should be

prepared for failure even after many years of training.

1. This article is most probably taken from ____. [ ]

A. a letter

B. an advertisement

C. a personal diary

D. a newspaper article

2. According to the passage, parents whose children show a special interest in sport ____. [ ]

A. feel uncertain if they should let their children train to be sports men or women.

B. try to get financial(财政的) support from the government for their children's training.

C. have to get medical advice from doctors about training methods.

D. prefer their children to be trained as young as possible.

3. Which of the following statements is NOT true? [ ]

A. By starting young, you won't have much time for your schoolwork.

B. Early training may damage your muscles.

C. Most children may become professional sports men after a long period of training.

D. It's very expensive for parents to support their child's development in sports.

4. The phrase "to take a second place" means ____. [ ]

A. to repeat the activities some other day

B. to become less important

C. of all the things, they are the most important

D. to happen again

5. ____ can become the best players after many years of training. [ ]

A. Most people

B. Some people

C. Hardly any people

D. No people