用一个50N的水平力，把一个200N的铁块从课桌的一端推到另一端，并掉到地面，设课桌面长为2m，高1m，则推力做的功是______J，重力做的功是______J，用到的公式有______、______．

I wonder how he could  _____ not handing in his maths exercises  yesterday, for his maths teacher is

always strict with his students. [ ]

A. get away with                                    

B. get down to

C. get along with                                  

D. get around