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 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 material, such as glass.
1. Annealing can make metal .
A.hardand tough(韧) B. hard but brittle C. soft but tough D. soft and brittle
2. Why do people put hot metal in water?
A.Tomake 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 depend 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 an 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.
31、(1分)
A well-known old man was being interviewed (采访) and was asked if it was correct that he had just celebrated his ninety—ninth birthday.
“That’s right.”said the old man. “Ninety—nine years old, and I haven’t an enemy in the world. They’re all dead.”
“Well, sir,”said the interviewer, “I hope very much to have the honour of interviewing you on your hundredth birthday.”
The old man looked at the yound man closely, and said, “I can’t see why you shouldn’t. You look fit and healthy to me!”
1. The old man said he had not an enemy in the world, which shows that he was a very .
A. friendly man he never made any enemies
B. healthy man he lived longer than all his enemies
C. lucky man his enemies had all died
D. terrible man he had got rid of all his enemies
2. When the interviewer said that he hoped very much to have the honour of interviewing the old man again the following year, .
A. he was trying to make the old man happy
B. he wished he himself would live another year
C. he did not believe the old man would live to be one hundred
D. he did not believe he would interview the old man again
3. When the old man said “I can’t see why you shouldn’t”, what he meant was:
A. “You must try to live another year to interview me again next year.”
B. “Of course, you can see me again since you’re so fit and healthy.”
C. “If I live to a hundred years, you should interview me again.”
D. “Unless you live another year, you wouldn’t be able to interview me again.”
4. What kind of man would you say the old man was?
A. He was silly. B. He was unpleasant.
C. He was very pround and sure of his health. D. He was very impolite to young people.
点击加载更多评论>>