题目

You can’t imagine ________ when they heard the news．        A．how they were excited    B．how excited they were        C．how excited were they    D．they were how excited 答案：Ｂ 解析: 略如图所示，在匀速转动的水平圆盘上，沿半径方向放着用细线相连的质量相等的两个物体A和B，它们与圆盘间的动摩擦因数相同，当圆盘转动到两个物体刚好还未发生滑动时，烧断细线，两个物体的运动情况是 ( )A. 两物体沿切线方向滑动B. 两物体沿半径方向滑动，离圆盘圆心越来越远C. 两物体仍随圆盘一起做圆周运动，不发生滑动D. 物体A仍随圆盘一起做匀速圆周运动，物体B发生滑动，离圆盘圆心越来越远