根据句意及词首字母或汉语提示，补全单词。
1. Hainan is in the s_____ of China.
2. —Don't you think English is a very u_____ language?
—Yes, I think so.
3. We Chinese r_____ the Great Wall as a symbol of China.
4. —Could you _____ (修理) the bike for me? It's broken.
—Of course. I'll do it now.
5. You'll be _____ (瘦的) if you eat less meat.