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速度与机械运动

> 下列说法正确的是 A.支点、力臂一定在杠杆上 B.动力作用点与阻力作用点一定在支点的两侧 C.滑轮组即可以省力，同时也可以省距离 D.摩擦力即可以是阻力，也可以是动力

问题：

发布时间：2024-09-12

下列说法正确的是

A.支点、力臂一定在杠杆上
B.动力作用点与阻力作用点一定在支点的两侧
C.滑轮组即可以省力，同时也可以省距离
D.摩擦力即可以是阻力，也可以是动力

参考答案：

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