问题 问答题 简答题

国际癌症研究机构将环境致癌物分为哪几类?

答案

参考答案:

(1)对人类致癌物:对人类的致癌证据充分,87种。

(2)对人类很可能或可能是致癌物:A类,对人很可能致癌,对动物致癌证据充分,但对人类致癌证据有限,63种。B类,对人可能致癌,即对人类和动物致癌证据均不充分,234种。

(3)现有的证据尚不能就其人类致癌性进行分类物:493种。

(4)对人类很可能不是致癌物:1种,即己内酯胺。

阅读理解

Do you know the story about Vince? It was a true story. Vince was an English boy and he was eight years old. He didn't like soap or water. Three or four times a day his mother said to him, “Vince, your hands are very dirty again.” Go and wash them. ” But Vince never washed them well. He only put his hands in the water for a few seconds and then took them out again.

Vince’s uncle and aunt lived in another city. One day they came to stay with Vince’s parents, and they brought their small son, Toby, with them. Toby was seven years old and he didn’t like soap or water, either. The boys sat with their parents for a few minutes and then they went outside. When they were playing, Vince looked at Toby's hands and then went back to Toby’s parents and said proudly (骄傲地), “Toby’s hands are dirtier than mine, ”

“Of course they are,”Toby said angrily. “You are one year older than I am, ”

小题1:Vince’s mother asked him to______ three or four times a day.

A.wash his hands

B.do his homework

C.clean his bedroom

D.wash his teeth小题2:When Vince saw Toby’s hands, he felt  ________.

A.sorry

B.proud

C.sad

D.terrible小题3:Vince’s hands were a little______ than Toby’s.

A.dirtier

B.cleaner

C.bigger

D.smaller小题4:From the story we know that_______ .

A.Vince liked soap and water, but Toby didn’t.

B.Toby liked soap and water,but Vince didn’t.

C.Vince and Toby liked soap and water.

D.Vince and Toby didn’t like soap or water.小题5:How many people are there in the story?   

A.Four.

B.Five.

C.Six.

D.Seven.

单项选择题