问题 选择题

下列关于物质用途不正确的是(  )

A.SO2可作食品的增白剂

B.高纯硅可制造光电池

C.O3可作自来水的消毒剂

D.Na2O2可作潜艇的供氧剂

答案

A.二氧化硫有毒,则SO2不能作食品的增白剂,故A错误;

B.硅可作为电池板的材料,则高纯硅可制造光电池,故B正确;

C.臭氧具有强氧化性,可作自来水的消毒剂,故C正确;

D.过氧化钠与水或二氧化碳反应生成氧气,则Na2O2可作潜艇的供氧剂,故D正确;

故选A.

完形填空
完形填空。
      Tom bought shoes from the shoe factory and tried to sell them to other people. There were not many
  1  in the small villages. People there didn't   2   to go to town to buy shoes" So Tom  3   a lot of shoes
there. One day Tom  4  along the street. He stopped in front of a house. There was a small boy
beside the door.
      Tom  5  the window of his lorry (货车) and asked the boy, "Is your  6  at home?"
     The boy looked at Tom and answered," Yes, she is. "
     "That's  7 " Tom said.
      He got off his lorry, look some  8  and  went to the door of the house, He knocked at the door and
waited for a few   9 , but nobody came to open the door. Tom knocked again, but still noon answered.
      Tom looked at the boy and said angrily, "Your mother is not at home!"
      "She is!" the boy said.
     "Why didn't she open the door?" Tom asked.
      "This isn't   10  house," the boy shouted.
( )1. A. shops  
( )2. A. know
( )3. A. made
( )4. A. moved
( )5. A. opened
( )6. A. father
( )7. A. well
( )8. A. dresses
( )9. A. hours
( )10. A. your  
B. towns  
B. want  
B. showed
B. passed
B. cleaned
B. mother
B. bad    
B. flowers
B. days  
B. their 
C. villages
C. went
C. sold
C. went    
C. found  
C. brother
C. good
C. jeans  
C. minutes
C. my      
D. stops
D. think
D. bought
D. drove
D. closed                                                   
D. sister
D. happy
D. shoes
D. weeks
D. his  
单项选择题