问题
填空题
若扇形OAB的面积是2cm2，它的周长是4cm，则该扇形圆心角的弧度数是______．
答案
设该扇形圆心角的弧度数是α，半径为r，
根据题意，有
，2r+αr=4
α?r2=21 2
解可得，α=2，r=1，
故答案为：2．
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若扇形OAB的面积是2cm2，它的周长是4cm，则该扇形圆心角的弧度数是______．
设该扇形圆心角的弧度数是α，半径为r，
根据题意，有
，2r+αr=4
α?r2=21 2
解可得，α=2，r=1，
故答案为：2．
完形填空（10分） Do you often think of your parents? You may say, "Of course, I 1 . I buy a present for my mother on Mother's Day and on Father's day I give my father 2 too." But what about the other days of the year? I have a friend whose parents live in another city. One day I went to see her. We had a nice talk. Then she wanted to 3 . So she dialed the number, but then she put down the phone. After about fifteen 4 , she dialed the number again, "Hi, Mom …" Later I asked, " 5 did you dial the number twice?" She smiled, "My parents are old and 6 . They can't get close to the telephone quickly. I always do so when I call them. I just want to give them 7 time to answer the call. " My friend is a good girl. She is 8 thinking about her parents. You also want to be a1child, right? Please remember to 10 your parents in every situation, not just on some important days.
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