问题 选择题

既能透过半透膜又能透过滤纸的是(   )

A.氯化钠溶液

B.淀粉溶液

C.酒精溶液

D.氢氧化铁胶体

答案

AC

【错解分析】任何事物都具有普遍性和特殊性,胶体知识也不例外。如胶体不一定是液体、胶体粒子不一定都带电(如淀粉胶体是分子型胶体)等。在胶体概念分析、性质应用等问题中,要注意胶体知识中的特殊性。

【正解】本题实际上是考查常见胶体的类别和胶体微粒直径大小问题。胶体只能透过滤纸(孔隙直径较大)而不能透过半透膜,淀粉溶液属于胶体(这是很多学生易出错的),故不能透过半透膜,本题常因忽视此点而错选B项。在各分散系中,只有溶液才能透过半透膜。

单项选择题
阅读理解

On the night of November 14, 1978,a six-year-old Korean boy was flying to the United  States. All he knew was that he was on a plane heading for somewhere. The plane landed at  Kennedy International Airport, where he was greeted by a family. This young boy was me.

I have grown up in a town where there were few Asians, so I stuck out in the crowd. I  made friends quickly and they treated me just like anyone else. You may ask if anyone made  fun of my appearance. Well, of course, I met that' kind of person. I just shrugged it off.

As an adopted child, I have something that others don't have. I have had the benefit of two  families. I'm lucky to have got a chance to start a new life. But we must try never to forget our  past. Someday I will go back to Korea to find out what kind of culture I left behind.

There is only one thing that I regret about being adopted. When I argue with my parents and they realize they are losing the argument, they sometimes wonder what I would be doing if  I were back in Korea. I don't understand this because I thought the purpose of adopting  someone was to give them a better chance of growing up in a family. Some day when I am  older, I want to adopt a girl and raise her the way my parents have raised me, but I would do it  better, for I know what went well and what did not.  

小题1:We learn that when the writer was on the way to his new family,______.

A.he was with his own parents

B.he was very happy and excited

C.he was about ten years old then

D.he didn't know he was going to be adopted小题2:If someone sticks out in the crowd, it means that he/she_______.

A.is very good-looking

B.is very kind-hearted

C.is easily noticed by others

D.is disliked by others小题3:When the writer was made fun of by others, he _______.

A.was deeply hurt

B.wanted to go back to Korea

C.didn’t care about it that much

D.tried to make friends with them小题4:What can we learn from Paragraph 3?

A.The writer wants to forget his past.

B.The writer isn't sad about being adopted.

C.The writer isn't interested in Korean culture.

D.The writer aren't know anything about Korea.小题5:What does the writer want to do when he is older?

A Go back to live with his parents in Korea.

B. Tell his parents what they have done wrong.

C. Find out how to raise children in a better way.

D. Adopt a girl and raise her in a good way.