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问题 选择题
在△ABC中，若sinA=
1
2
且∠B=90°-∠A，则sinB等于（　　）
A．
1
2
B．
2
2
C．
3
2
D．1
答案

∵△ABC中，sinA=

1
2
且∠B=90°-∠A，

∴∠A=30°，∠B=90°-∠A=60°．

∴sinB=

3
2
．

故选C．

完形填空

阅读下面短文，按照句子结构的语法性和上下文连贯的要求，在空格处填入一个适当的词或使用括号中词语的正确形式填空，并将答案填写在答题卷标号为16—25的相应位置上。

I have met many interesting people. I'll tell you about one of them. Many years ago, when I worked   16 a volunteer at Stanford Hospital, I got to know a little girl    ___17____ (name) Liza who was suffering from a rare and serious disease. Her only chance of  _18___ (recover) appeared to be a blood transfusion from    19___  five-year-old brother,    20_  had survived the same disease and developed the antibodies needed to combat the illness. The doctor explained the situation to her little brother, and asked the boy   __21  he would be willing to give his blood to his sister. I saw him hesitate for a moment    before taking a deep breath and saying, "Yes, I'll do it if it will save Liza."

As the transfusion progressed, he lay in a bed next to his sister,  22  (smile).   __23_  then his face grew pale and his smile faded. He looked at the doctor and asked with   24__  trembling voice, "Will I start to die right away?"

Being young, the boy had misunderstood the doctor. He thought he was going to have to give her  25_ his blood.
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多项选择题

网络数据库的常用类型有（）。

A.教育资源库

B.学术类网络数据库

C.在线图书馆

D.娱乐欣赏类数据库
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