Ответ:

1. S I have never understood (never / understand) that rule.

2. How long have you been (you / be) ill?

3. How long has Dima been playing (Dima/play) volleyball?

4. We have been laughing (laugh) for 10 minutes.

5. We have known (know) each other for ages.

6. Valery has been travelling (travel) since Monday.

7. I have wanted (want) to have a dog since I was 5.

8. Alice has not had (not/have) a pet for about a year.

9. Mum has been cooking (cook) for hours.

10. You have been talking (talk) for ages.

11. They have loved (they/love) hiking since their childhood?

Ответ: See above.