选词填空 [[QOrDeR]]My mother ________ to work.( ) A. walking B. walks C. walk 【小题2】He is ________ years old.( ) A. eighteenth B. eight C. eighth 【小题3】We ________ a happy family.( ) A. is B. are C. am 【小题4】He goes to work by ________.( ) A. a bus B. bus C. buses 【小题5】We like to ________ the animals at the zoo.( ) A. watch B. watches C. watching