写出动词的过去式。
1. dance __________ 2. talk __________
3. are __________ 4. do __________
5. am/is __________ 6. help __________
7. have/has __________ 8. phone __________
9. walk __________ 10. cook __________
11. look __________ 12. listen __________
13. watch __________ 14. play __________