如图所示,在水平力F的作用下,重为G的物体沿竖直墙壁匀速下滑,物体与墙之间的动摩擦因数为μ,物体所受摩擦力大小为
A.μ(F+G)
B.μF
C.G
D.μ(F-G)
BC
— How many of them do you want to act in the play?
—_______ , and still a large number needed!
A.All
B.Both
C.Neither
D.None