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【简答题】
设边长为2 a 的正方形的中心 A 在直线 l 上，它的一组对边垂直于直线 l ，半径为 r 的⊙ O 的圆心 O 在直线 l 上运动，点 A 、 O 间距离为 d ． 小题1:如图①，当 r ＜ a 时，根据 d 与 a 、 r 之间关系，请你将⊙ O 与正方形的公共点个数 填入下表： 小题2:如图②，当 r ＝ a 时，根据 d 与 a 、 r 之间关系，请你写出⊙ O 与正方形的公共点个数。 当 r ＝ a 时，⊙ O 与正方形的公共点个数可能有____个； 小题3:如图③，当⊙ O 与正方形有5个公共点时， r =____（请用a的代数式表示r，不必说理）
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举一反三
【简答题】先化简，再求值： 6 m 2 -9 ÷ 2 m-3 - m m+3 ，其中m=2．
【单选题】Unable to defeat him by logical discussion, she ______ her old habit of criticizing his speech.
A.
fell back on
B.
looked down upon
C.
lived up to
D.
hanged on to
【单选题】When I talked about the thing，I felt Jane watching me uncomfortably，looking________ she wished to speak.
A.
as though
B.
even though
C.
so that
D.
in case
【简答题】先化简再求值： 3 m 2 + 1 2 (2 m 2 -4m)-2( m 2 -3m) ，其中m=-2．
【简答题】先化简，再求值： m m+3 - 6 m 2 -9 ÷ 2 m-3 ，其中m=-2．
【简答题】听力题 1. Why was Nancy unhappy? A. There was too much homework for her to do. B. She had no time to spend on her hobbies. C. She quarreled with her best friend. 2. What will Nancy do to say sorry to Luc...
【单选题】听力原文：M: Do you think Susan could help us plan the trip to Canada? W: Well, since she spends every winter there, she might know a thing or two about it. Q: What does the woman mean? (14)
A.
Susan will help if she's there this winter.
B.
Canada has many unexplored areas.
C.
Susan would probably be a good person to ask.
D.
The tourists should try to get a lot of information.
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