阅读下面材料，在空白处填入适当的内容（不多余3个单词）或括号内所给单词的正确形式。
Mr. Li:  OK, listen up! _____ we can enjoy ourselves on the Great Wall, there are a few rules and ______(suggest). OK?
All:      Yes, Mr. Li.
Mr. Li: First, you must keep to the path. You mustn’t walk along the edge because you might fall and hurt yourself. Is that clear?
All:     Yes.
Mr. Li:  And you have to keep together. You mustn’t go off _____ your own, because you might get _____(lose).
All:    OK, Mr. Li.
Jack:  Can we have something _____(eat) now? I’m starving.
Mr. Li:  No, you can’t, Jack! You only ______(have) breakfast an hour ago. I think we should start walking, and then stop at noon for our picnic. But you shouldn’t drink all the water, because you may need some __(late).
Jack:   Can we go rock climbing?
Mr. Li: Yes, you can, ____ you must use ropes. You have to think about ____(person) safety! And you must have the right shoes. OK, I think that’s all. Let’s go down this path, and then we can cross the stream and climb up to the top of that mountain. Then we can take ___ look across the countryside...
Jack:   ...and have lunch?
Mr. Li: ...and then walk along that part of the wall, up there. Come on! I’ll lead the way.
Jack:   I feel tired already. I may need a rest very soon.