Question

Annealing is a way of making metal softer by heating it and then letting it cool very slowly. If metal is heated and then cooled very quickly , for example by dipping it in water , it will be very hard but also very brittle(脆)---that is , It will break easily. Metal that has been annealed is soft but does not break as easily . It is possible to make metal as hard or as soft as is wished, by annealing it. The metal is heated, and allowed to cool slowly , for a certain length of time. The longer the heated metal takes to cool slowly , the softer it becomes . Annealing can also be used on other materials, such as glass.

1. Annealing can make metal _______________.

A．hard and tough (韧)                      B．hard but brittle

C．soft but tough                          D．soft and brittle

2. Why do people put hot metal in water ? ____________

A．To make it hard                         B．To make it soft

C．To make it cool                         D．To make it brittle

3. As suggested by the text , how can glass be made less brittle ?____________

A．It can be heated and then cooled quickly

B．It can be cooled and then heated slowly

C．It can be heated and then cooled slowly

D．It can be cooled and then heated quickly

 

Answer 1

【答案】

1.C

2.A

3.C  

【解析】

试题分析：文章介绍了一种冶金的方法：annealing（退火）是将工件加热到适当温度，然后进行缓慢冷却，目的是使金属组织更细，更坚硬。

1.细节题：从文章的句子Annealing is a way of making metal softer by heating it and then letting it cool very slowly. 和It is possible to make metal as hard or as soft as is wished, by annealing it.可知金属通过annealing可以变得柔软和坚韧。选C

2.细节题：从文章的句子：by dipping it in water , it will be very hard but also very brittle(脆)可知把热的金属放进水里可以使金属变硬。选A

3.推理题：从文章的句子：The longer the heated metal takes to cool slowly , the softer it becomes .可知玻璃也是加热后慢慢冷却可以变得坚韧。选C  

考点：考查科普类短文

点评：文章虽然是科普类短文，但篇幅很短，内容浅显易懂，此类文章一般集中考查细节题，考生可以先审题，再看文章，这样就可以提高阅读的速度和效率。采用针对性方法进行阅读。