试题与答案

下列说法正确的是 A.CO2的水溶液能导电,所以CO2是电解质;液溴不导电,所以

题型:选择题

题目:

下列说法正确的是

A.CO2的水溶液能导电,所以CO2是电解质;液溴不导电,所以液溴是非电解质

B.BaSO4不溶于水,其水溶液的导电能力极弱,所以BaSO4是弱电解质

C.某物质经分析,只含有一种元素,则此物质一定是一种单质

D.强电解质溶液的导电能力不一定比弱电解质溶液的导电能力强

答案:

答案:D

题目分析:A、溶于水或在熔融状态下能够自身电离出离子的化合物是电解质,溶于水和在熔融状态下都不能够自身电离出离子的化合物是非电解质。CO2不能电离,属于非电解质。单质既不是电解质,也不是非电解质,A不正确;B、硫酸钡溶于水的部分完全电离,因此硫酸钡是强电解质,即电解质的强弱与化合物的溶解性无关系,只与电解质的电离程度有关系,B不正确;C、只含有一种元素的物质不一定是单质,也可能是混合物,例如氧气与臭氧组成的物质,C不正确;D、溶液的导电性只与溶液中离子的浓度和离子所带的电荷数有关系,所以强电解质溶液的导电能力不一定比弱电解质溶液的导电能力强,D正确,答案选D。

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题型:阅读理解

阅读短文,根据要求完成下面各小题。

       As teenagers, you have many dreams. These dreams can be very big, such as winning the Nobel

Prize, or they can be small. You may just want to become one of the ten best students in your class.

       Once you find a dream, what do you do with it? Do you ever try to make your dream true?    

       Follow Your Heart by Australian writer Andrews tells us that making our dreams true is life’s

biggest challenge (挑战).    

       In fact, everyone can make his dream come true. The first thing you must do is to remember what

your dream is.    

       Don’t let it leave your heart. Keep telling yourself what you want. Do this step by step and your

dream will come true faster because a big dream is, in fact, many small dreams.    

       You must also never give up your dream.

       There will be difficulties on the road to your dreams. But the biggest difficulty comes from yourself.

You may think you’re not very good at some school subjects, or it is impossible for you to become a

writer. These kinds of thoughts stop you from getting your dream, the book says.

       You need to decide what is the most important. Studying instead of watching TV will lead to better

exam results, while saving five yuan instead of buying an ice cream means you can buy a new book. As

you get closer to your dream, it may change a little. This is good as you have the chance to learn more

skills and find new interests.

1. Translate the sentence underlined in paragraph 7 into Chinese.

___________________________________________________________________________

2. Find out the sentences from the passage that stand for "the biggest difficulty comes from yourself".

                                                                                                                                                     

3. What should you do if you want to make your dream come true? (至少两条)

__________________________________________________________________________

4. What’s the main idea of the last paragraph?  

__________________________________________________________________________

5. 请给短文拟定一个适当的英文标题。

__________________________________________________________________________

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