问题 不定项选择题

在大气层中,因CO2的含量不断增加而引起“温室 效应”,造成大气中CO2含量增加的主要原因是  [ ]

A.由于动植物呼吸作用增加

B.由于实验室逸出的CO2增加

C.由于森林绿化面积迅速递减,使得自然界吸收CO2的能力降低

D.由于大量燃烧矿物燃料

答案

CD

完形填空

阅读下面短文然后从各题所给的三个选项中选出最佳选项。

Helen 's favorite food is chocolate. Her parents and teacher often say that it's        for her teeth to eat too much chocolate. But she doesn't believe it. She often puts some chocolate in the milk for breakfast, the juice         lunch, even the soup for supper. Her mother has to        some chocolate in her bag before she goes to school. Sometimes when her mother goes shopping with her, Helen won't leave the shop        her mother buys some chocolate for her.

The little girl        back from school with a painful(痛苦的) look yesterday afternoon. A tooth hurt and she had nothing. Her mother made some soup for her. But she put some chocolate in it. Her father bought some       for her, but she put some chocolate in it, too. Of course it was useless.       the next morning her mother took her to see the      .The dentist saw there was a cavity(洞) in her bad tooth .So he had to fill(填充)it with something.

“Now, young girl,” said the dentist , “What kind of filling(填充物) would you like for that tooth ?”

     , please,” answered Helen. The dentist and Helen’s mother both laughed. The dentist asked Helen to eat fresh fruit and vegetables        chocolate. And it’s necessary for Helen to have healthy eating habits.

小题1:A. good    B.  bad C.  well

小题2:A. for B.  with    C.  at

小题3:A. get B.  put C. buy

小题4:A. when    B.  if C.  until

小题5:A. go  B.  came    C.  returned

小题6:A. medicines   B.  pills   C.  medicine

小题7:A. But B.  So  C.  And

小题8:A. doctor  B.  nurse   C.  dentist

小题9:A. Chocolate   B.  Milk    C.  Fruit

小题10:A. instead    B.  but C.  instead of

单项选择题