你不许在黑板上画画 再问： 谢谢 那 you must return the books in time ？ 再答： 你必须及时返还那些书 再问： you must not step the grass ? 再答： 你不许踩草地 再问： you must put back the books after you have read them . you must not talk to drivers when the bus is moving . youmust clean the classroom every day. you must not jump the queue when you wait in line for the bus . you must put away the balls after you have used them. 这些那 ？帮帮我
