A:wash and dre
B:are washed and dressed
C:will wash and dre
D:were washed and dressed
如图所示,已知mA=2mB=3mc,它们距轴的关系是rA=rC= 12 rB,三物体与转盘表面的动摩擦因数相同,当转盘的速度逐渐增大时( )