问题 问答题

A、B组成的黑色混合物,按如图进行实验:

(1)写出下列物质的化学式:A______B______E______

(2)写出有关反应的化学方程式:①______;②______.

答案

由于A、B组成的黑色混合物高温时可以生成红色固体D和气体C,所以可知D是铜,则A和B是氧化铜和碳组成的混合物,C是二氧化碳,且C能与A反应生成气体E,所以可知A是碳,E是一氧化碳;一氧化碳也能和氧化铜反应生成铜,所以可知B是氧化铜;

(1)由以上分析可知A、B、E的化学式分别是 C、CuO、CO;

(2)①是碳与氧化铜的反应,方程式为:C+2CuO

 高温 
.
 
2Cu+CO2↑;②是碳与二氧化碳的反应,方程式为C+CO2
 高温 
.
 
2CO;

故答案为:(1)C; CuO; CO;(2)①C+2CuO

 高温 
.
 
2Cu+CO2↑;②C+CO2
 高温 
.
 
2CO;

选择题
阅读理解

阅读理解。

     A year ago, I paid no attention to English idioms, though my teacher emphasized (强调) the importance again and again. But soon, the importance of English idioms was shown in an amusing experience.

     One day, I happened to meet an Englishman on the road, and soon we began to talk. As I was talking about how I was studying English, the foreigner seemed to be astonished. Gently shaking his head,

shrugging his shoulders, he said, "You don't say!" "You don't say!" I was puzzled. I thought, perhaps this is not an appropriate topic (适当的话题). "Well, I'd better change the topic." So I said to him. "Well, shall we talk about the Great Wall? By the way, have you ever been there?" "Certainly, everyone back home

will laugh at me if I leave China without seeing it. It was magnificent." He was deep in thought when I

began to talk like a tourist guide. "The Great Wall is one of the wonders in the world. We are very proud

of it." Soon I was interrupted again by his words:"You don't say!" I couldn't help asking, "Why do you ask me not to talk about it?" "Well, I didn't request you to do so, " he answered, greatly surprised. I said, "

Didn't you say' you don't say?" Hearing this, the Englishman laughed to tears. He began to explain, 'You

don't say' actually means 'really!' It is an expression of surprise. Perhaps you don't pay attention to English

idioms." Only then did I know I had made a fool of myself. Since then I have been more careful with

idiomatic expressions. Remember: what the English teachers said is always right to us students.

1. A year ago, I paid no attention to English idioms because _______.

A. English idioms were not important  

B. I was not careful with English idioms

C. my teacher didn't emphasize the importance of them  

D. I had no interest in them

2. At first, on hearing "You don't say," I thought the foreigner meant _______.

A. he was not interested in the topic  

B. he was only interested in the Great Wall

C. I had talked too much            

D. I had to stop talking

3. The underlined word in the first paragraph probably means _______.

A. interesting

B. important

C. terrible

D. unlucky

4. Which of the following is true according to the passage?

A. The Englishman left China without seeing the Great Wall.

B. The Englishman wanted to see the Great Wall after I talked about it.

C. The Englishman wanted me to act as his guide.

D. The Englishman visited the Great Wall and thought it worth visiting.

5. After the Englishman explained the idiom, _______.

A. I thought the Englishman had made me a fool  

B. the Englishman became a real fool.

C. I felt very silly          

D. I became more carefully in everything