Don't throw litter around.Please____.(A).pick it up(B).pick up it(C).pick up them(D).pick them up
问题描述:
Don't throw litter around.Please____.(A).pick it up(B).pick up it(C).pick up them(D).pick them up
litter是不可数,为什么正确答案是(D)而不是(A)呢?
答
litter 是个集体名词