把You mustn't drop litter in the schoolyard改为同义句怎么改? litter in the schoolyard.

来源：学生学帮网编辑：学帮网时间：2024/07/06 22:47:31

把You mustn't drop litter in the schoolyard改为同义句怎么改?
______ ______litter in the schoolyard.

don't drop