Question

Annealing

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(浸) 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 breaks 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 material, such as glass.

1. Annealing can make metal ____

　　A. hard and tough(韌)　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. In annealing, the required hardness of a metal depends on 　______

　　A. the quantity of water used　B. the temperature of the metal

　　C. the softness of the metal　  D. the timing of the operation

4. 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

1---4   CADC 

解析:

1.此題屬詞句意義理解題。文章第一句“Annealing is a way of making metal sofer”。第三句“Metal that has been annealed is soft but does not break as easily”．其中“does not break as easily”的意思就是“tough”．因此C項符合要求。A和D兩面中均有一方面與上文不符。B中兩方面均不符。因此都被排除。C為正確答案。

2.本題屬推斷歸納題。文中第一句：”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”.意思是說如果把金屬加熱，然后迅速放到水里冷卻，也就會變得非常硬，但也變得脆。“bald”是工藝的主觀目的。“brittle”是伴隨的客觀結果。因此選A而不選D,B項與題目不符:C項是手段不是目的。因此，都可被排除。A為正確答案。

3.此題屬概括歸納題。timing是時間的選擇。本答案的依據(jù)是5和6兩句，“The metal is heated，… length of time．”“The longer…the softer it becomes．”，“。cool”的時間是可以控制的，時間越長就越“soft”，即硬度就越低。由此我們可得出結論：在退火過程中，金屬的硬度是受到冷卻的時間長短影響的。文章中沒有提到退火時使用的水的數(shù)量，沒有提到金屬的溫度，也沒有提及金屬的軟度。因此這三答案均被排除。D為正確答案。

4.此題屬推理判斷題。文中最后一句說“Annealing can also be used on other materials ,such as glass.”很明顯退火這工藝同樣可用于象玻璃一類的其他材料。文中我們已知“annealing”就是先“heat”后“。cool slowly”．由此推斷C是正確的。A項中“Cooled quickly”不符合上述工藝要求。B和C工藝程序都不對。因此，A、B、D三項被排除。C為正確答案.