问题 选择题

碘原子的结构示意图如右图所示。生活中常见的是碘-127(127为相对原子质量),而核反应中产生的则是碘-131(131为相对原子质量)。下列有关它们的说法不正确的是

A.碘-127与碘-131所含质子数均为53

B.碘-127与碘-131所含电子数相同

C.碘-127与碘-131属于不同元素

D.碘元素人体摄入不足或过多均会造成甲状腺肿大

答案

答案:C

题目分析:由图可知,碘-127与碘-131具有相同的质子数,且属于同一类原子,所以他们属于同一种元素,他们原子所含的电子数相同,所含的中子数不同;碘元素人体摄入不足或过多均会造成甲状腺肿大。

点评:原子结构示意图属于中考中的热点题型,出现率较高,但是并不难,注意仔细审题,另外元素周期表中前二十号元素排列要会背诵。

阅读理解

阅读理解。

     I shook hands with my father in the truck, and for a long time he looked straight ahead and didn't say a

word. But I knew he was going to say a little to me. "I can't tell anything," he finally said. "I never went to

college, and none of your brothers went to college. I can't say 'don't do this and do that', because everything

is different and I don't know what is going to come up. I can't help much with money either, but I think

things will work out."

     He gave me a new check-book. "If things get pushing, write a small check. But when you write one,

send me a letter and let me know how much. There are some things we can always sell." In four years all

the checks I wrote were less than a thousand dollars. My part-time jobs such as reading to the blind student

and sitting with the teachers' kids filled in the financial gaps.

     "You know what you want to be, and they'll tell you what to take," my father went on. "When you get a

job, be sure it's honest, and work hard." I knew that soon I would be alone in the big town, and I would be

missing the cool winds and a life where your thinking was done for you.

     Then my dad reached down beside his seat and brought the old, broken Bible that he had read so often,

the one he used when he wanted to look something up in a friendly quarrel with one of the neighbours. I

knew he would miss it. I knew, though, that I must take it.

     He didn't say, "Read this every morning." He just said, "This can help you if you will let it."

     Did it help? I got through college without being a burden on the family. I have been able to make money

since.

1. What is the writer's main purpose (目的) in writing this passage?

A. To tell the readers his life story.

B. To tell people what kind of person his father was.

C. To let people know how poor he was.

D. To tell the readers what present he got from his father.

2. Why did the father not ask his son not to do this and do that?

A. Because he felt quite confident of him.

B. Because he was born from a poor family.

C. Because he was a man of few words.

D. Because he didn't want to be much too strict with him.

3. What would you learn from this passage?

A. How to live by oneself.

B. How to stand on one's own feet.

C. What a good father should do.

D. What the self-important is like.

4. What may be the proper Chinese meaning for the underlined part in the passage?

A. 闲暇时光

B. 学费

C. 经济不足

D. 精神空虚

5. What kind of book did the Bible seem to be to the writer's father?

A. It was a book which told you how you should get on well with others.

B. There were many good examples for you to copy in it.

C. It was a book that told you how to get a good job and a good future.

D. It was a good book that could help you when you were in trouble.

单项选择题