问题 选择题

下列叙述,正确的是(  )

A.SiO2制成的玻璃纤维,由于导电能力强而被用于制造光缆

B.用一束光线通过氯化钠溶液和蛋白质溶液,能看到相同的现象

C.SO2和Cl2通入品红溶液,品红均褪色,说明两者的漂白原理相同

D.浓硝酸具有强氯化性,能使铝钝化,故常用铝罐车运输冷的浓硝酸

答案

A.SiO2制成的玻璃纤维,由于传导光能力强而被用于制造通讯光缆,故A错误;

B.蛋白质溶液是胶体,具有丁达尔现象,氯化钠溶液无丁达尔效应,故B错误;

C.二氧化硫能与有色物质结合生成无色物质,氯气有强氧化性,能将有色物质氧化为无色物质,故C错误;

D.铝在冷的浓硝酸中钝化,可用铝罐车运输冷的浓硝酸,故D正确.

故选D.

单项选择题 共用题干题
阅读理解

阅读理解。

    While I was in 9th grade, I built a circuit for the traffic system of our city. After getting the first prize, I

got this valuable advice from my father, "Do whatever interests you, and don't let the work challenge you,

make sure you are challenging that work."

    I have always preferred the projects which are challenging and related to real life problems. I clearly

remember building a shipping program several years ago. I divided the whole project into several small

sections. When I understood it clearly, used my brainstorming skill on it, and gave some basic ideas. Then

I asked my professor for help before jumping into coding. At first, I did not know how to ask questions

correctly and always asked the question "How do I do it?" As I kept working and discussed with my professor,

I became more comfortable and those"How" questions soon turned into "What if I do this and that" types o

f questions.

    It took me four days to write the code. The desire to solve the problem kept me sleepless all nights

brainstorming in even greater details. Every time I saw my program running smoothly, I exploded with joy.

I still remember the last day of my work. I was getting some problem and didn't know what to do. At that

moment, a man came in to clean. He has headphones, and he was dancing while cleaning the room. Seeing

this, I burst out laughing. That moment calmed me. I regained energy and interest and started to work again,

and soon I fixed the problem.

    My success in the project proved that breaking up a large problem into small parts could help find a

possible solution. Discussing the problem with others was also very beneficial. Now I have gained the

confidence to attempt any kind of project.

1. According to the passage, the writer was interested in _____. [ ]

A. developing traffic systems

B. doing challenging projects

C. winning great prizes

D. writing different codes

2. The writer asked the question "How do I do it" at first because _____.[ ]

A. he had no clear idea about his program

B. he was too shy to express himself

C. he wanted to he understood easily

D. he preferred this kind of question

3. We learn from the passage that the writer's shipping program _____.[ ]

A. would benefit people a lot

B. was done together with others

C. was difficult and needed patience

D. cost much money and energy

4. What would be the best title of the passage? [ ]

A. Do It Yourself

B. No Pains, No Gains

C. Learning with interest

D. Practice Makes Perfect