The chief engineer of the high-speed railway ________ Shanghai to Beijing always devotes most of his time ________ his work.
下列有关声现象的说法中不正确的是（ ）
如图所示，质量为m的小滑块，由静止开始从倾角为θ的固定光滑斜面顶端A滑至底端B，A点距离水平地面的高度为h，则小滑块到达B点时重力的瞬时功率为____，小滑块从顶端A滑至底端B这个过程中重力的平均功率为____．
