剂量率是决定低LET辐射生物效应的重要因素,总剂量一定时,剂量率越低,照射时间越长,

题型:单项选择题

问题:

剂量率是决定低LET辐射生物效应的重要因素,总剂量一定时,剂量率越低,照射时间越长,生物效应就()。

A.越加重

B.无明显变化

C.越减轻

D.有时加重有时减轻

E.不能肯定

考点:放射卫生(医学高级)放射卫生(医学高级)题库
题型:单项选择题

阅读理解。 

     Fred and Jane are brother and sister. They are American. They are in the same school. Their school is not far (远) from their home.

     Fred is in Mr. Black's class. He is thirteen. He is one of the best (最好的) student in his class. Mr.

Black likes him very much. He does well in (善长于) Chinese, but Mr. Black is not.

     Jane is eleven. She is in Mrs. Black's class. Mrs. Black teaches English. Jane is good at English, but

she is not good at Chinese.

1. Fred and Jane are _________.

A. Chinese.

B. English

C. friends

D. American

2. Jane is ________.

A. good at Chinese

B. in Mr. Black's class

C. not good at English

D. Fred's sister

3. ________ is good at Chinese.

A. Fred

B. Jane

C. Mr. Black

D. Mrs. Black

4. Mrs. Black is ________.

A. a Chinese teacher  

B. a teacher of English

C. one of the best student

D. Jane's mother

5. Which is NOT right?

A. Fred and Jane are in the same family

B. Mr. and Mrs. Black are Fred and Jane' parents

C. Mr. Black doesn't do well in Chinese

D. Mrs. Black is Jane's English teacher.

题型:单项选择题

鼓励病人提问

题型:单项选择题

计算机按照处理数据的形态可以分为

A.巨型机、大型机、小型机、微型机和工作站

B.286机、386机、486机、Pentium机

C.专用计算机、通用计算机

D.数字计算机、模拟计算机、混合计算机

题型:单项选择题

简述性压抑的含义。

题型:单项选择题

配对秩和检验中,n<5不能得出()结论。

A.方差齐性

B.方差不齐

C.均数相同

D.均数不同

E.差异有统计学意义

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