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问题 填空题

在△ABC中，与∠A相邻的外角是100°，要使△ABC是等腰三角形，则∠B的度数是______．

答案

∵∠A的相邻外角是100°，

∴∠A=80°．

分两种情况：

（1）当∠A为底角时，另一底角∠B=∠A=80°；

（2）当∠A为顶角时，则底角∠B=∠C=

180°-80°
2
=50°

（3）当∠B是顶角时，∠B=180°-2∠A=20°．

综上所述，∠B的度数是80°或50°或20°．

故答案是：80°或50°或20°．

单项选择题

When I lived in Spain, some Spanish friends of mine decided to visit England by car. Before they left, they asked me for advice about how to find accommodation. I suggested that they should stay at "bed and breakfast" houses, because this kind of accommodation gives a foreign visitor a good chance to speak English with the family. My friends listened to my advice, but they came back with some funny stories.
"We didn’t stay at bed and breakfast houses," they said, "because we found that most families were away on holiday. "
I thought this was strange. Finally I understood what had happened. My friends spoke little English, and they thought "VACANCIES" meant "holidays", because the Spanish word for "holiday" is "vacation". So they did not go to house where the sign outside said "VACANCIES", which in English means there are free rooms. Then my friends went to house where the sign said " NO VACANCIES", because they thought this meant the people who owned the house were not away on holiday. But they found that these houses were all full. As a result, they stayed at hotels!
We laughed about this and about mistakes my friends made in reading other signs. In Spanish, the word "DIVERSION" means fun. In English, it means that workmen are repairing the road, and that you must take a different road. When my friends saw the word "DIVERSION" on a road sign, they thought they were going to have fun. Instead, the road is blocked by a crowd.
English people have problems too when they learn foreign languages. Once in Paris when someone offered me some more coffee, I said "Thank you" in French. I meant that I would like some more. However, to my surprise the coffee pot was taken away! Later I found out that "Thank you" in French means "No, thank you".

When someone offered me more coffee and I said " Thank you" in French, I ______.

A．didn’t really want any more coffee
B．wanted them to take the coffee pot away
C．really wanted some more coffee
D．wanted to express my politeness
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问答题 简答题

如何理解规范的6．1．4条？
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