问题
单项选择题
下列平面图形是直角三角形的为（）。
A.A
B.B
C.C
D.D
答案
参考答案：B
解析：
本题主要考查的知识点是平面的投影特性。
[要点透析] 选项B所示直线AC为正平线，且在正立面a'b'⊥a'c'，因此空间中AB⊥AC，故△ABC为直角三角形。
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下列平面图形是直角三角形的为（）。
A.A
B.B
C.C
D.D
参考答案：B
解析：
本题主要考查的知识点是平面的投影特性。
[要点透析] 选项B所示直线AC为正平线，且在正立面a'b'⊥a'c'，因此空间中AB⊥AC，故△ABC为直角三角形。
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| We were having such bad weather in London that my wife suggested spending Christmas week in 1 Italian seaside hotel which we visited last summer. I thought this idea over for a day or two and then 2 to go. When I asked my brother 3 I could borrow some money from him, he advised me against going 4 at that time of year but finally 5 help us when I promised faithfully 6 him back the money from my next month's salary (工资). The manager of a local tourist office (旅游公司) 7 us some advice and useful 8 about our journey, hotels and the type of clothes to take with us. "You'd better 9 London at least two days before Christmas if you can, if not earlier. And I hope you enjoy 10 very much." | ||||
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