问题 不定项选择题

在照相底片定影时,硫代硫酸钠(Na2S2O3)溶液能溶解掉未起反应的溴化银,这是因为银离子与硫代硫 酸根离子生成配离子。银离子的配位数为2,若硫代硫酸钠与溴化银刚好完全反应,则所得溶液中的溶 质为 [    ]

A.[Ag(S2O3)2]Br和NaBr

B.Na3[Ag(S2O3)2]

C.Na3[Ag(S2O3)2]和NaBr

D.Na[Ag(S2O3)2]

答案

答案:C

阅读理解

阅读理解。

     Children's schooling is changing very fast. In the past, teachers kept children sitting still for hours. They

made them memorize (记住) different kinds of things. In other words, the children had to go on repeating

things until they knew them "by heart". Today, many want to know if it's possible to make children learn all.

They say they can only help them learn. They say they must let children learn and find out things themselves.

      But for some children, school is a kind of prison (监狱). They are there only because their parents make

them go. They get out of the classroom as soon as the teacher lets them leave. Many of them want to find

work, but the law will not let them work until they reach a certain age. And so, they have to stay in school.

Often they do not learn anything at all and hate school every moment.

1. The word "schooling" in the passage means _____.

A. 学费

B. 教育

C. 锻炼

D. 训练

2. Which of the following has the same meaning to "go on repeating"?

A. read and write

B. read or write once

C. read or write twice

D. read or write again and again

3. Now, the teachers try their best to _____.

A. make their students learn more in class

B. teach their students how to learn themselves

C. make their students do everything they say

D. ask their students to do more exercises after class

4. Some children hate schools because _____.

A. they hope to spend much time reading

B. their teachers aren't friendly to them

C. they regard them as prisons

D. they are angry with their classmates

5. _____, so they want to stop to find work.

A. Some children need some money

B. Some children dislike staying in school

C. Some children fall behind their classmates

D. Some children come from poor families

问答题