问题 选择题

下列实验操作符合规则的是(  )

A.为了便于观察,给试管里的液体加热时,试管口可以对着实验者

B.为了操作方便,对于没有毒和腐蚀性的药品,可以用手直接拿

C.为了节约药品,剩余药品应倒回原试剂瓶,以免浪费

D.为了防止试剂污染,滴管应悬空在试管上方滴加液体,不要直接接触试管

答案

A、为了安全,给试管里的液体加热时,试管口不可以对着有人的方向.操作错误.

B、对于没有毒和腐蚀性的药品,也不可以用手直接去拿,会污染药品.操作错误.

C、实验剩余的药品不能放回原瓶,否则会污染药品.操作错误.

D、为了防止试剂污染,滴管应悬空在试管上方滴加液体,不要直接接触试管,操作正确.

故选D.

阅读理解

阅读理解。

     Bruce's favorite food is chocolate. His parents and teachers often say that it's bad for his teeth to eat too

much chocolate. But he doesn't believe it. He often puts some in the milk for breakfast, the juice for lunch,

even the soup for supper. His mother has to put some chocolate in his bag before he goes to school. Sometimes when she goes shopping with him, he doesn't leave the shop until his mother buys some chocolate for him.

     The little boy came back from school with a painful look yesterday afternoon. A tooth hurt and he had

nothing for supper. His mother made some soup for him. He wanted to put some chocolate in it, or he refused

to drink it. His mother had to agree. His father bought some medicine for him, but it was of no use. So this

morning his mother took him to the dentist. The dentist found that there was a cavity (洞) in his bad tooth.

So he had to fill it with something.

     "Now, young man," said the dentist, "What kind of filling (填充物) would you like for that tooth?"

     "Chocolate, please," answered Bruce.

1. What does Bruce like best?

   _______________________________________________________

2. His mother has to put some chocolate in his bag. (改为一般疑问句)

    ____ his mother ____ to put ____ chocolate in his bag?

3. He doesn't leave the shop until his mother buys some chocolate for him. (改为同义句)

   He ____ ____ the shop ____ she buys some chocolate for him.

4. What does the word "refuse" mean in Chinese?

   _______________________________________________________

5. What kind of filling would Bruce like for his bad tooth?

   _______________________________________________________

单项选择题