问题
选择题
已知△ABC中，AB=1.5，AC=2，sinB=
|
答案
∵△ABC中，c=1.5，b=2，sinB=
，2 3
∴由正弦定理得：
=b sinB
，c sinC
∴sinC=csinB b
=1.5× 2 3 2
，又c＜b，1 2
∴C＜B，
∴C=30°．
故选A．
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已知△ABC中，AB=1.5，AC=2，sinB=
|
∵△ABC中，c=1.5，b=2，sinB=
，2 3
∴由正弦定理得：
=b sinB
，c sinC
∴sinC=csinB b
=1.5× 2 3 2
，又c＜b，1 2
∴C＜B，
∴C=30°．
故选A．
| 完形填空。先通读下列短文，掌握其大意，然后从A, B, C, D四个选项中选出最佳答案。 | ||||
| Someone says, "Time is money." But I think time is 1 important than money. Why? Because when money is spent, we can get it back. However, when time is 2 , it'll never 3 . That is 4 we mustn't waste time. It goes without saying that the 5 is usually limited. Even a second is very important. We should make full use of our time to do 6 useful. But it is a pity that there are a lot of people who 7 know how important time is. They spent their limited time smoking, drinking and playing. They do not know that wasting time means wasting part of their own 8 . In a word, we should save time. We shouldn't 9 today's work for tomorrow. Remember we have no time to 10 . | ||||
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