问题 填空题

(8分)在有机化合物分子中,常把连有4个不同的原子或原子团的饱和碳原子称为不对称碳原子,可用*C标记,例如:

丙烷进行氯代反应中,可分离出4种二氯代物A、B、C、D,分子式均为C3H6Cl2。当它们进一步氯代为三氯代物时,A只有一种三氯代物,B有2种三氯代物,C和D各有3种三氯代物,已知C具有不对称碳原子,试写出A、B、C、D的结构简式:A________ B___________ C____________ D___________。

答案

  A为; B为

C为; D为

分子式为C3H6Cl2的同分异构体有:CH2ClCHClCH3、CH2ClCH2CH2Cl、CH(Cl)2CH2CH3、CH3C(Cl)2CH3。因为当它们进一步氯代为三氯代物时,A只有一种三氯代物,说明A中含有的氢原子都是相同的,故A的结构简式为CH3C(Cl)2CH3。B有2种三氯代物,因此B为CH2ClCH2CH2Cl。由于C具有不对称碳原子,因此C为CH2ClCHClCH3。则D为CH(Cl)2CH2CH3

阅读理解

阅读理解。

     Peter is thirteen years old.  He is in Grade Two this year.  He likes to watch football matches.

And he often reads newspapers. He does his best to know where and when there is going to be a

football match.  Now Peter is having lunch.  He is listening to the radio,  too.  Hc is vcry happy

because there is going to bc a nice football match on TV at four this afternoon.

       He wants to watch it very much.  But he is going to have English and Chinese lessons.  He thinks

hard and finds a way.

       "Hello,  Mrs Black,"  Peter says to his teacher ori the telephone,  "Peter is ill in bed. He wants to

ask for half a day's lcave. "

     "Oh, I'm sorry to hear that," says Mrs Black. 'But who's that? "

      "It's my father,  Mrs I31ack. "

1.  Peter is a _____.         

A.  micidlc school student              

B.  Young Pioneer

C.  worker                    

D.  teacher

2.  Pcter will be in  _____ next year.      

A. Grade One    

B. Gracle Two    

C. Grade Three  

D. Grade Four

3.  Peter often reads newspapers because _____.          

A.  he likes to read news

B.  he likes to read stories

C.  he wants to know where and when there is going to be a football match

D. his father wants him to read them

4.  Peter wants to ask for half a day's leave because_____ .         

A.  his father is ill in bed

B.  he wants to watch the football match

C.  he doesn't like to have English and Chinese lessons

D.  he is ill in bed

5.  Which sentence is RIGHT?   

A.  Mrs Black is going to take Peter to see a doctor.

B.  Peter likes to watch TV at four in the afternoon.

C.  Peter is a stupid boy.

D.  Peter isn't an honest boy.

问答题