根据中文或者首字母提示用单词的正确形式完成句子。
1. You should drink ________ ________ (许多)water.
2. How many times do you _________ _________ (刷牙)?
3. The doctor is very busy right now. He is __________ (检查) the patient now.
4. I’m feeling t________. I cough day and night.80.
It's a good h_______ to go to bed early.
5. We sleep ________ _________(至少) 8 hours every day.
6. We should try to ________ (改善)our environment.