A,B为两个相同的绕着轻绳的定滑轮,A滑轮挂一质量为M的物体,B滑轮受拉力F,而且F=Mg。设A,B两滑轮的角加速度分别为βAβB,不计滑轮与轴的摩擦,则有
A campus emergency ______ occur at any time of the day or night, weekend, or holiday, with little or no warning.
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