词形转换。
1. their(同音词)________  2. sun (同音词)__________
3. big(反义词)_________   4. clever(同义词)________
5. two(同音词)_________   6. have(单三形式)_______
7. who(所有格)________    8. teacher(动词)_________
9. old(反义词)_________   10. story(复数)_________