1. foot (复数)               ___________
2. balance (形容词)       ___________
3. babysit (现在分词)    ___________
4. bike (同义词)            ___________
5. active (名词)             ___________
6. little (比较级)            ___________
7. far (比较级)              ___________
8. stop (过去式)            ___________
9. nine (序数词)            ___________
10. free (反义词)           ___________