题目

--- When will you be through with your work, Jones? ---      ? My boss usually finds something for me to do at the last minute． A．Who knows                                     B．Would you help me C．I beg your pardon                     D．Anything the matter 答案：A一物体放在倾角为θ的斜面上，被向下轻轻一推刚好匀速下滑，若给它一个沿斜面向上的速度v0，求它沿斜面向上滑动的最大距离是多少？