一、适当形式填空(单句适当形式)（共5小题；共5分）
1. Barbecue is a favourite way of (entertain) friends.
2. We (gradual) get used to getting up early in the morning and going to bed late at night.
3. We talked until the early hours, and (consequence) we overslept.
4. I knew that concentration(专心) was the first (require) for learning.
5. Many people were poisoned by the (poison) mushrooms.
