问题 问答题 简答题

试分析包晶反应不平衡组织的形成过程。

答案

参考答案:实际生产中的冷速较快,包晶反应所依赖的固体中原子扩散往往不能充分进行,导致包晶反应的不完全性,即在低于包晶温度下,将同时存在参与转变的液相和相,其中液相在继续冷却过程中可能直接结晶出相或参与其他反应,而相仍保留在相芯部,形成包晶反应的非平衡组织。

阅读理解

阅读理解

     We drink tea every day. But more than three hundred years ago most of the people in

Europe(欧洲) did not know anything about tea. Some people heard about it, but very few

of them know what to do with it.

     There is a story about an English sailor(水手) who went to countries in the east, the west

and the south. He went to India and China. One day he came home and brought some tea as

a present for his mother. She told her friends about the present and asked them to a "tea party".

When her friends came to the "tea party", the old woman gave them brown tea-leaves. The old

woman's friends began to eat them. Of course, nobody liked the tea-leaves.

     At that time the sailor came in. He looked at the table and said, "Mother,what did you do

with the tea?"

     "I boiled it,as you said."

     "And what did you do with the water?"

     "I threw it away(扔掉),of course." answered the old woman.

     "Now you may throw away the leaves,too," said her son.

1. Most of the people in Europe __________ 300 years ago.

A. drank tea every day

B. knew everything about tea

C. knew nothing about tea

D. liked to eat the tea-leaves

2. One day the English sailor brought his mother some tea from __________.

A. countries in the west

B. countries in the south

C. India or China

D. a tea shop in England

3. The sailor's mother asked her friends to her house, because __________.

A. the sailor told her to

B she liked to show off(炫耀)

C. she wanted to ask her friends what to do with the tea

D. she wanted to taste the tea together with her friends

4. At the "tea party", __________.

A. all the woman's friends spoke highly of(高度评价) the tea

B .nobody knew what to do with the tea

C. the woman didn't eat the tea-leaves

D. the woman gave her friends each a glass of tea water

5. What mistake(错误) did the old woman make? She __________.

A. boiled the tea

B. did as the sailor said

C. threw away the water

D. didn't throw away the tea-leaves

填空题