根据句意及汉语提示写单词,完成句子.

1. I've already           (付款) for that book.

2. The ____      (政府)has done a lot to protect the wild animals.

3.____        (天然的)food is good for our health.

4.1 will remember my first teacher____         (永远)．

5. We must take a____         (科学的)approach to the problem.