根据句意及首字母提示补全单词

1. Kangkang's father is a doctor. He is very busy right now. He is e_______ the patients.

2. —Would you m_______ lending your dictionary to me?

    —Not at all. Here you are.

3. Tom, staying up late is bad for your h_______, so go to bed early next time.

4. I'm feeling t_______. I cough day and night.

5. We should try to i_______ our environment.