问题 填空题

铁在生产生活中有着广泛的用途,它在地壳中的含量仅次于铝,约占地壳质量的5.1%.由于化学性质比较活泼,所以在地壳中以化合物的形式存在.赤铁矿是很常见的一种铁矿石,其主要成分是氧化铁.

(1)用化学方程式表示赤铁矿炼铁的原理______.

(2)小明拆开某种食品包装袋时,发现其中有一小袋抗氧化剂,撕开后发现袋内有板结的铁锈.小明推测该抗氧化剂的有效成分是______.它除了有延缓食品被氧化变质的作用外,还有______作用.

答案

(1)氧化铁和一氧化碳反应生成铁和二氧化碳的化学方程式为:3CO+Fe2O3

 高温 
.
 
2Fe+3CO2

(2)铁在与氧气和水充分接触时容易生成铁锈,这样铁在做抗氧化剂的同时也起到了干燥的作用.故填:铁;防潮.

阅读理解

阅读理解。

  A man went to buy a piece of meat. As he didn't know how to cook meat, he asked the butcher

(屠夫) to tell him the way of cooking it. The butcher told him how to cook it, "But I can't remember your

words," the man said. "Will you please write them down for me?" The butcher was kind enough to write

them down for him. The man went home happily with the meat in his hand and the note (字条) in his

pocket (口袋). A dog followed him on the way. It jumped at him, took the meat away and ran off. The

man stood there, not knowing what to do. Then he laughed and said, "never mind. You don't know how toeat it. The note is still in my pocket."

1. The man went to buy a piece of meat in _______.

A. restaurant      

B. shop      

C. butcher's      

D. chemist's

2. Why did the man asked the butcher to tell him the way to cook meat?

A. He wasn't good at cooking meat.

B. He can't cook meat very well.

C. He didn't know how to cook meat.

D. He didn't know how to eat meat.

3. In order to (为了)remember what the butcher said, he asked the butcher _______.

A. to say it once again.          

B. to teach him again.

C. to show him how to cook it.    

D. to write it down for him.

4. What happened in the end?

A. He forgot to cook the meat.

B. The dog took the meat away.

C. He taught(教)the dog how to eat the meat.

D. The note is still in his pocket.

5.What do you think of the man?

A. He was afraid of dogs.

B. He loved dogs very much.

C. He was a very foolish(愚蠢的)man.

D. He didn't know how to do things.

单项选择题