Sure, here are the best answers to complete the sentences:

1. He regrets **being** lazy last year. He lost his job.
2. Willy denied **eating** a whole bag of chocolate chip cookies before lunch.
3. I was delighted **to see** my old friends again.
4. We regret **to inform** you that we cannot approve your suggestion.
5. Couldn't help **laughing** at his jokes.
6. Tom offered **to give** Jane a ticket to the theater, but she refused to take it.
7. Those workers stopped **drinking** their coffee because they felt tired of their work.
8. He asked them **to help him**.
9. Mr. Minh advised my family **against** leaving Vietnam.
10. I hope **to see** that woman again.
11. Have you ever considered **becoming** a pharmacist?
12. You had better **stay** at home until you feel better.
13. I remember **hearing** my mother said the grass in the garden needed cutting.
14. My teacher doesn't allow us **to talk** while he is explaining the lesson.
15. We have plenty of time. We needn't **hurry**.