一 、单选
1、 Look！ He _____their mother do the housework.
A. is helping B. are help
C. is help D.is helpping
2 、_____are the boys doing ？ They are singing in the room.
A .Who B .How
C.What D.Where
3、 Dont talk here. My mother _____.
A. is sleeping B .are sleeping
C. sleeping D .sleep