根据短文内容，填写所缺单词或用所给单词的正确形式填空。
Once upon a time, a lion 1. (catch) a mouse. The mouse said, “Please don’t eat me! I 2. (help) you one day.” The lion laughed but let the mouse go. Later, some hunters caught the lion 3. a net. The lion could not get 4. . He felt very sad. Then, the little mouse came. He bit through the net with his sharp 5. (tooth). The lion 6. (be) free! He thanked the little mouse. 7. the mouse said, “You laughed at me before, 8. even a small mouse can help a big lion.” This story 9. (teach) us that we should be kind to everyone, because even 10. (weak) ones can help the strongest sometimes.

1. caught
2. will help
3. in
4. out
5. teeth
6. was
7. The
8. but
9. teaches
10. the weakest