A.功率越大,做功越多
B.功率越大,做功越快
C.功率越大,越省力
D.功率越大,机械效率越大
答案:B
The crowd cheered wildly at the sight of their favorite star, who was reported _______ the Film World Award.
A.winning
B.having won
C.to have won
D.to win
气球上升到100米的高空时,从气球上脱落一个物体,物体又上升了10米后开始下落,若取向上为正方向,则物体从离开气球开始到落到地面时的位移是____________米,通过的路程为____________米。