问题 填空题

一同学用某种粗盐进行提纯实验,步骤见下图。

请回答:

(1)步骤①和②的操作名称是________。

(2)步骤③判断加入盐酸“适量”的方法是____________________________________;步骤④加热蒸发时要用玻璃棒不断搅拌,这是为了防止_________________________,当蒸发皿中有较多量固体出现时,应______________________,用余热使水分蒸干。

答案

(1)过滤 (2)滴加盐酸至无气泡放出为止 局部过热造成固体(或溶液)飞溅 停止加热(或熄灭酒精灯)

 

题目分析:(1)步骤①和②的操作名称是过滤,因为经过操作后实现了固液分离;(2)步骤③判断加入盐酸“适量”的方法是滴加盐酸至无气泡放出为止,步骤④加热蒸发时要用玻璃棒不断搅拌,这是为了防止局部过热造成固体(或溶液)飞溅,,当蒸发皿中有较多量固体出现时,应停止加热,用余热使水分蒸干

阅读理解

阅读理解

     There are some differences in replying to compliment between Chinese and Americans. Americans

tend to accept the compliment while Chinese generally murmur(低语)some reply about not being worthy

of the praise. Here are two examples.

     A young Chinese woman in the U.S. was complimented for the lovely dress that she was wearing.

"It's graceful. The colors are so beautiful!" She was pleased but somewhat embarrassed. In typical

Chinese fashion, she replied, "Oh, it's just an ordinary dress that I bought in China."

     At a reception in an American college, a newly-arrived Chinese scholar was chatting with the hostess, who was an old friend. As an acquaintance(熟人)of hers came up, she said, "Ron, let me introduce

Mr. Chen, an outstanding physicist and one of the nicest people I know." Mr. Chen offered his hand to

the newcomer but looked at his hostess and said with a smile, "Should I feel ashamed, or should I tell him

you don't really mean it?"

     In both cases, the words of the Chinese conveyed a message quite different from what was intended.

In the case of the Chinese woman, the reply could have meant that the one paying the compliment did

not know what a really good dress is; otherwise, how could she get so excited about an ordinary dress?

The implication(暗示)was that the American woman's taste in clothing was questionable. In the second

case, if Chen had not been smiling, he could have meant "You're just saying that to be polite; you don't

really mean that." So in one case, the person had poor judgment. In the other case, the hostess was not

sincere. Quite a gap between intention and message!

1. Which word can best replace the underlined word compliment in Paragraph 1?

A. praise

B. complaint

C. explanation

D. blame

2. Two examples are given in the passage to           .

A. amuse the readers

B. draw readers' attention

C. support the author's opinion

D. arouse readers' interest

3. The following statements are true except           .

A. both stories happened in the USA

B. Mr. Chen achieved achievements in physics

C. the dress was a beautiful one

D. Mr. Chen worked in the USA for long

4. The passage mainly tells us           .

A. Americans like to praise people

B. Chinese people are very modest

C. culture varies in different countries

D. people should respect each other

名词解释