问题 选择题

金属铜与人体分泌物中的盐酸以及子宫内的空气反应可生成超氧酸:Cu+HCl+O2=CuCl+HO2  HO2 (超氧酸)不仅是一种弱酸而且也是一种自由基,具有极高的活性。下列说法或表示正确的是

A.氧化剂是O2

B.HO2在碱中能稳定存在

C.氧化产物是HO2

D.1 mol Cu参加反应有2 mol电子发生转移

答案

答案:A

阅读理解

阅读理解。

Dear Jimmy,    

     Something terrible happened to me several days ago. When I wake up in the morning, I often take

a shower and then have a sandwich and a cup of coffee for breakfast before I go to class. But that

morning was different.     

     It was on June 24. The alarm clock didn't work, so I got up late. It was about time for me to go

to class. I had to do everything quickly. I didn't have enough time to do the things as usual.    

     I went straight to my school, but later I remembered that I forgot to turn off the gas (煤气) in the

kitchen. I asked my teacher for permission to go back to my house by taxi.     

     When I got home. I saw much smoke all around. I ran quickly to turn off the gas. If I came back a

bit late, nothing would be left.    

     I was really frightened. From then on, I woke up early to get everything ready before I went out

of my home. You should also check (检查) everything before you leave your house. Take care!

                                                                                                                                Yours, Bruce

根据短文内容,选择正确答案。

1. Bruce ____ first after he usually wakes up.

A. does exercise    

B. drinks coffee    

C. takes a shower    

D. has a sandwich

2. Bruce was late for school because ______.

A. he went to bed late    

B. he forgot the classes    

C. he didn't prepare things    

D. his clock was broken

3. Bruce went back home by ___________.

A. bus    

B. taxi    

C. bike    

D. subway

4. The underlined word "permission" means "___________"in Chinese.  

A. 允许        

B. 同情      

C. 教训    

D. 劝告 

5. The letter is about ______________.

A. a boring class      

B. a bad day    

C. a traffic accident    

D. the importance of gas

单项选择题