Here are potential ways to finish the second sentences for each item:

1. Peter is sick.
**=> Peter was sick.**

2. My speaking skills improve.
**=> My speaking skills improved.**

3. We don’t maintain traditions.
**=> We didn’t maintain traditions.**

4. They are selfish.
**=> They were selfish.**

5. I know the answer.
**=> I knew the answer.**

6. She isn’t hard-working.
**=> She wasn’t hard-working.**

7. Anna doesn’t feed the cattle.
**=> Anna didn’t feed the cattle.**

8. I don't know her number, so I don't phone her.
**=> If I knew her number, I would phone her.**

Feel free to adjust if there's a specific format needed!