A:wash
B:washing
C:washes
- Would you like to tell me ______?
- Sure. Practice makes perfect.
幂函数y=f(x)的图象经过点4,12则f(2)= ( )
光滑水平桌面上有A、B两个物块,B的质量是A的n倍.将一轻弹簧置于A、B之间,用外力缓慢压A、B.撤去外力后,A、B开始运动,A和B的动量大小的比值为( )