问题 单项选择题 B型题

机体接触苯乙烯的生物监测指标是()

A.尿中马尿酸的测定

B.尿中甲基马尿酸的测定

C.尿中苯乙醇酸和苯乙醛酸的测定

D.尿中β2-微球蛋白的测定

E.尿中三氯乙酸的测定

答案

参考答案:C

解析:慢性镉暴露引起肾损害时,肾小管吸收功能障碍,引起尿中低分子蛋白增多,其中最具代表性的是β2-微球蛋白。机体吸收的甲苯在体内代谢成马尿酸,大部分由尿排出,是常用的甲苯生物监测指标。机体吸收的苯乙烯在体内可代谢成为苯乙醇酸和苯乙醛酸,由尿中排出。因此,可作为苯乙烯的生物监测指标。机体吸收的三氯乙烯在体内代谢成三氯乙酸,由尿排出。尿中三氯乙酸的浓度与接触外剂量有相关关系,因此已作为生物监测指标。

填空题

阅读短文,根据短文内容及首字母提示,在空白处填入一个适当的单词。

       Ron, the teacher at the skydiving (跳伞运动) school, was surprised when the gray-haired man said that his

name was Walter and asked if he could take skydiving lessons. Ron asked him how old he was and he

(1) r           that he was 60. Ron explained to Walter that (2) a            over 50 had to be checked by a doctor

before he could learn to jump from a plane. "I'm sorry, but I can't let you start learning (3) w            a letter

from your doctor."

       Walter smiled. "Here is a letter from my doctor. He asked me to take (4) l             of tests and he says that

I'm fine."

       So Walter was able to join the skydiving school. He came to all the lessons and worked very (5) h          .

Soon it was the time for him to make his (6) f             jump. Ron asked him if he was feeling OK. Walter

answered that he had never felt better. However, he added that there was something he should have told Ron

(7) e           . Ron asked what it was and Walter smiled. Then just before he jumped, he told Ron that he wasn't

60. Ron asked how old Walter (8) r            was and Walter told him he was 75!

       Walter has a lot of (9) h           . He enjoys riding fast motorbikes and (10) c            mountains. Last year

he was saved by a police helicopter (直升飞机) in Wales.

       His daughter Betty worries about him. "I think he should stop all these activities. But my mother says that

as long as he's happy, it's OK."

判断题