问题 选择题

下列定性分析正确的是

A.Cl2、SO2均能使品红溶液褪色,说明两者均有氧化性

B.SiO2、Al2O3均可和酸与碱反应,说明两者均为两性氧化物

C.浓硫酸、浓硝酸在常温下均能使铁铝钝化,说明两者均有强氧化性

D.钠、铁的金属性均比铜的强,说明两者均可以从硫酸铜溶液中置换出单质铜

答案

答案:C

题目分析:A、Cl2溶于水生成的次氯酸具有强氧化性,SO2具有漂白性,二者均能使品红溶液褪色,但褪色原理不同,A不正确;B、能和酸以及碱反应都生成盐和水的氧化物是两性氧化物,氧化铝是两性氧化物。但二氧化硅只能和氢氟酸以及强碱反应,因此不是两性氧化物,B不正确;C、浓硫酸、浓硝酸均有强氧化性,在常温下均能使铁铝钝化,C正确;D、钠是活泼的金属,极易与水反应生成氢氧化钠和氢气,因此钠和硫酸铜溶液反应生成氢氧化铜、硫酸钠和氢气,得不到铜,铁可以置换出铜,D不正确,答案选C。2、浓硫酸、浓硝酸、钠、铁的性质以及两性氧化物的判断

阅读理解

阅读理解。

    When you are learning a language, listening, speaking and writing are important, but reading can

also be very helpful. When you read, you can not only learn some new words, but also learn how to

use them. When you read a passage, it gives you a good example for writing.

    Here are some good reading tips.

    Firstly, try to read at the right level (水平). Read something that you can understand. If it is too

hard for you, it is not interesting.

    Secondly, try to understand the new words. If there are four or five new words on a page, don't

use a dictionary. Instead, try to guess their meanings as you read. Mark (作标记) them with a pencil.

Then look them up in a dictionary when you finish reading, and write them in your own vocabulary

book. Try to remember them.

    Thirdly, try to read for a short time once a day. Fifteen minutes or half an hour every day is better

than two hours every Sunday. For example, you can read before you go to bed, or after you get up

or at lunchtime.

    Lastly, read something that interests you. Choose a newspaper, a book or a magazine about a

subject that you like. It will be easy enough for you to understand.

1. The underlined word "tips" in the passage means "   '' in Chinese.

A.  末端        

B.  小费        

C.  处所      

D.  建议

2. How many reading tips does the writer give us?

A. Six.          

B. Five.        

C. Four.      

D. Three.

3. If you meet a few new words on a page while reading, you can____. 

A. stop reading

B. guess the meanings at first

C. write them down at once

D. look them up right away

4. Which of the following is TRUE according to the passage?

A. Reading a lot can help you write better.

B. It is useful for you to read for long once a week.

C. When you read, you can only learn some new words.

D. Try to read something hard to make your English better.

5. Which is the BEST title for the passage?

A. How to look up a new word    

B. How to make reading better    

C. How to remember new words

D. How to choose something to read

选择题