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问题 选择题
若a=
2005×2006
2007×2008
，b=
2006×2007
2008×2009
，c=
2007×2008
2009×2010
，则有（　　）
A．a＞b＞cB．a＞c＞bC．a＜c＜bD．a＜b＜c
答案

a÷b=

2005×2006
2007×2008
÷
2006×2007
2008×2009
=
2005×2006
2007×2008
×
2008×2009
2006×2007
=
(2007+2)×(2007-2)
2007×2007
=
2007×2007-4
2007×2007
＜1，所以a＜b；

b÷c=

2006×2007
2008×2009
÷
2007×2008
2009×2010
=
2006×2007
2008×2009
×
2009×2010
2007×2008
=
2006×2010
2008×2008
=
(2008-2)×(2008+2)
2008×2008
=
2008×2008-4
2008×2008
＜1，所以b＜c；

所以a＜b＜c；

故选：D．

填空题

A: What’s the date today
B: It’s June 16.
A: (16) Then it’s Dragon Boat Festival today, isn’t it
B: Yes. (17)
A: Did you have rice dumplings this morning
B: Sure. (18)
A: I didn’t.
B: What a pity! But I happen to have got some with me. (19)
A: I’d love to. By the way, why do you call it Dragon Boat, Festival
B: Because in China, people race dragon boats this day every year.
A: Oh, I see. (20)
B: You are welcome.
A．We Chinese usually eat rice dumplings this day
B．I hate eating rice dumplings.
C．Thank you for your rice dumpling.
D．I don’t think so.
E．Would you like to have one
F．Already
G．How about you
查看答案
多项选择题

在剩余电流动作保护器的保护范围内发生电击伤亡事故，应（）。

A.拆除剩余电流动作保护器

B.增设剩余电流动作保护器

C.检查剩余电流动作保护器的动作情况

D.分析未能起到保护作用的原因
查看答案