1 . ---What does the sign over there read?
---“No person ______ smoke or carry alighted cigar or pipe in this area.

2 . The guard warned, ＂You ________ pay more attention to your behavior next time, young man.＂

3 . —To work in the deep water is dangerous. What should we do?
—________the robots have a try?

4 . Our school makes it a rule that students ________ have lunch and supper in the dining room. (用适当的词填空)