问题 填空题

回答下列问题:

(1)实验室配制100g 10%的氯化钠溶液时,需要           g氯化钠固体。

①称量时如果用质量为23.1g的烧杯盛放固体,在托盘天平上已放30g的砝码,则天平上的游码位置应是下图的           (填字母)。

②下列仪器中,量取水时需要用到d和            仪器(填序号),溶解时需要用到e和           仪器(填序号)。

a.烧杯、b.10mL量筒、c.100mL量筒、d.滴管、e.玻璃棒、f.药匙、g.蒸发皿。

(2)在粗盐提纯中,将氯化钠溶液蒸发至有较多量固体析出后,应            ,并用玻棒不断搅拌,利用余热将余下溶液蒸发至干。

答案

(1)10

① B

② c;a

(2)停止加热(或熄灭酒精灯)

阅读理解

阅读理解。

     We each have a memory. That's why we can still remember things after a long time. Some people

have very good memories and they can easily learn many things by heart, but some people can only

remember things when they say or do them again and again. Many of the great men of the world have

got surprising memories.

      A good memory is a great help in learning languages. Everybody learns his mother language when

he is a small child. He hears the sounds, remembers them and then he learns to speak. Some children are

living with their parents in foreign countries. They can learn two languages as easily as one because they

hear, remember and speak two languages every day. In school it is not so easy to learn a foreign language

because the pupils have so little time for it, and they are busy with other subjects, too.

     But your memory will become better and better when you do more and more exercises.

1. Some people can easily learn many things by heart because _______.

A. they always sleep well

B. they often eat good foot

C. they read a lot of books

D. they have very good memories

2. Everybody learns his mother language _______.

A. at the age of six

B. when he is a small child

C. after he goes to school

D. when he can read and write

3. Before a child can speak, he must _______.

A. read and write

B. make sentences

C. hear and remember the sounds

D. think hard

4. In school the pupils can't learn a foreign language easily because _______.

A. they have no good memories

B. they have no good teachers

C. they don't like it

D. they are busy with other subjects

5. Your memory will become better and better _______.

A. if you have a lot of good food

B. if you do more and more exercises

C. if you do morning exercises every day

D. if you get up early

单项选择题 A2型题