问题 选择题

下列氢氧化物中,受热最不易分解的是

A.Fe(OH)3

B.Cu(OH)2

C.NaOH

D.Al(OH)3

答案

答案:C

题目分析:大多数金属氢氧化物受热易分解为氧化物和水,而活泼金属(如K、Ca、Na等)的氢氧化物不易分解。A项Fe(OH)3受热易分解为Fe2O3和H2O,B项Cu(OH)2受热易分解为CuO和H2O,D项Al(OH)3易分解为Al2O3和H2O,只有C项 NaOH 受热不易分解。   

点评:熟悉金属氢氧化物的性质,此题属于简单题型

阅读理解

阅读理解。

Dear friends,

    I’m a middle school student. I work hard and I’m good at studying, but I feel unhappy all day, because

I have some problems. I am always stressed out(有压力的), because my parents and teachers all hope

that I can go to a very good university. I have to study from morning to night. On weekends, my parents

don’t let me meet friends or talk with friends on the phone. I can’t play computer games, either. They ask me to have piano lessons every Sunday afternoon. They don’t care whether (是否) I like it or not. Having lessons , doing homework and practicing the piano are all my life. I find it difficult to get relaxed. I really

want to have time to do the things I like , but I don’t know what to do. Can you help me?

                                                                                                                                             Yours,

                                                                                                                                             A lonely boy

1.The boy always feels _______.

A. excited

B. angry

C. happy

D. stressed out

2. His parents want him to_______.

A. live in the school

B. keep healthy

C. leave school

D. go to a good university

3. The boy _______ on weekends.

A. must practice the piano

B. can meet friends

C. can talk on the phone

D. can play computer games

4. The underlined word “ care ”means_______.

A. 改变

B. 关心

C. 打乱

D. 记录

5. Which of the following is NOT TRUE ?

A. The boy works hard.

B. The boy is good at studying.

C. They boy doesn’t have to study all day.

D. The boy can play the piano well.

单项选择题