A Concert

    The Newtown School will have a concert on Children's Day. Ann, Ken and David will play together in the concert. Ann will play the piano, Ken will play the guitar, and David will play the drums. Mocky will not play in the concert, but he will go, too.

    All the children and their parents are at the concert, but David will not be there because he is not well today. Who will play the drums? Ken and Anil are worried. But Mocky can play the drums. Believe it or not, he can play really well.

把加工一批零件的任务按3：2：1分配给赵、钱、孙三位工人师傅，三人计划同时开工，并且可以同时完工．实际工作时，钱师傅被调走，赵、孙两人按计划效率同时开工，同时完成全部任务时，赵师傅实际的工作量比分配给他的工作量多加工300个零件，孙师傅实际的工作量比分配给他的工作量多加工（　　）个零件．