问题 选择题

下列说法中正确的是

A.α粒子散射实验揭示了原子的可能能量状态是不连续的;

B.由于每种原子都有自己的特征谱线,故可以根据原子光谱来鉴别物质;

C.用电磁波照射某原子,使它从能量为E1的基态跃迁到能量为E2的激发态,则该电磁波的频率等于

D.氢原子的核外电子从n=4能级轨道向低能级轨道跃迁所辐射的光子的频率最多有8种。

答案

BC

题目分析:α粒子散射实验揭示了原子的内部模型,A错;由于每种原子都有自己的特征谱线,故可以根据原子光谱来鉴别物质,B对;由,C正确;氢原子的核外电子从n=4能级轨道向低能级轨道跃迁所辐射的光子的频率有6种,D错。

阅读理解

Recently in the hope of earning both money and social experience, I became a door-trw door salesman.

I once read a saying. “If somebody wants something of yours, you will be treated as warmly as spring, but if they don’t you may be treated as coldly as winter.” You may consider this an exaggeration (夸张), but if you are a salesman, it is clearly correct.

You would never have found it to be so true if you hadn’t been a salesman. You needn’t stand doubtful looks and unfriendly comments; you needn’t listen to something completely wrong and nod to say that it was quite right, you needn’t worry about being refused time after time; you needn’t always keep patience and a smile; you needn’t repeat the same sentences over and over again; you needn’t talk to somebody you dislike ....

I did this work for a month, then I decided to give it up; Apart from the reasons above, I found I was paying too much attention to the job and thus sacrificing my study time. The latest test result proved that my grades were getting worse.

Even worse, I hadn’t enough time to join my classmates in college activities. Some times 1 felt lonely and unhappy because of both my study and my part-time job. Now I don’t think it is worth doing such a thing for even though I was earning money it came at great cost.

Newspapers and magazines often publish stories about excellent students who do part-time work while also keeping high scores in class. But according to my experience, park-time work can have some strong negative influences on study.

Most students don’t view the relationship between study and work correctly. In my opinion, if it isn’t a must for financial reasons, students should be careful about taking up a part-time job.

小题1: From the text, we can tell that the writer is _____.    

A.an unemployed man

B.a middle-school student

C.a college student

D.a door-to-door salesman小题2:Which of the following words has the closest meaning to the underlined word “sacrificing”? 

A.Losing

B.Wasting

C.Using

D.Getting小题3:The writer thought_____. 

A.doing a part-time job was unnecessary

B.part-time jobs had good effect upon study

C.it was hard to deal with the relationship between study and work

D.part-time jobs would be good for every college student小题4:What would be the best title for the text _____.

A.Part-time Jobs Are Useful

B.Part-time Jobs Can Cost Dear

C.Students Shouldn’t Take Part-time Jobs

D.Part-time Jobs Are Important to Many Students

单项选择题 A1/A2型题