You should go to see him when he is so seriously ill. _____, he is your brother. [ ]

A. In all

B. At all

C. Above all

D. After all

如图所示的动滑轮重5N，不计绳重和摩擦，用力F匀速提起重为45N的重物，并使其升高1m，则拉力所做的有用功为______J，额外功为_______J，此装置的机械效率为_________。