=
=
=
=

( )
B .
C . 70
D .
︰21

下图是制作滑轮组时的两种不同的绕线方法,请说一说这两种绕法产生的效果有什么不同。

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A. He does exercise every morning. B. Last week. C. 1000-meter race, throwing, tree climbing. D. The weather was fine. E. Liu Zhaoyang was the first. |
:
化成最简单的整数比是,比值是.
x=
:
D .
:

北京
℃
①老牛的身子被他刷的干干净净。
②水被织女泼出门外。