问题 选择题

下列说法正确的是(  )

A.NaHCO3的电离方程式为:NaHCO3=Na++H++CO32-

B.金属氧化物不一定是碱性氧化物

C.在碱性溶液中能大量共存的离子为:Fe3+、Na+、Cl-、SO42-

D.SO3溶于水,其水溶液能导电,SO3是电解质

答案

A、碳酸氢钠电离生成碳酸氢根和钠离子,正确应为:NaHCO3═Na++HCO3-,故A错误;

B、过氧化钠不是碱性氧化物,故金属氧化物不一定是碱性氧化物,故B正确;

C、碱性溶液中Fe3+能够生成氢氧化铁沉淀,无法共存,故C错误;

D、SO3溶于水,其水溶液能导电,导电的是生成的硫酸电离的离子,不是三氧化硫电离的离子,故SO3不是电解质,故D错误;

故选B.

问答题
阅读理解

阅读理解。

Dear Editor,

     I'm a Senior 1 student in a middle school. This term, my favourite teacher, Miss Mao, no longer teaches

us. I want to see her, but I'm afraid that she no longer likes me and I don't want to trouble her. I really miss

her. What should I do? 

                                                                                                                                             Tian Yan

Dear Tian Yan,

     It's bad luck that you have lost your favourite teacher. But, if she is still in your school, nothing can stop

you going to see her. When she isn't busy, ask her if she minds having a quick chat. You can then tell her

she was your favourite teacher. Everyone is happy to know they are liked!

     If she has left the school, it will be more difficult to meet her. It will be hard, but remember people always

come and go in our lives. We can't rely on (依靠) them being with us all the time.

     You may be sad to say goodbye to her, but we can remember and learn from her. Think of her best

qualities. 

     You could also try looking for similar qualities in your other teachers. Study hard and give your new

teacher a chance. In time, you might start to see that he or she has different qualities to learn from.

      Finally, you can not completely rely on other people getting you through your studies, or even your life. 

                                                                                                                                                Editor

1. Tian Yan ______. [ ]

A. is a troublemaker

B. likes Miss Mao very much

C. is happy these days

D. doesn't like to tell her secret to anyone

2. Which of the following does the editor advise Tian Yan NOT to do? [ ]

A. Find a time to see Miss Mao.

B. Have a short chat with Miss Mao.

C. Tell Miss Mao she likes her.

D. Keep quiet about the thing.

3. The expression"in time" in this passage means "______". [ ]

A. over a period of time

B. on time

C. at the right time

D. a long time ago

4. According to the passage, students can make progress in their studies ______. [ ]

A. completely by their favourite teachers

B. completely by their favourite classmates

C. mainly by their parents

D. mainly by themselves