Choose the right tense form.

1. We haven’t been having/ haven’t had a holiday for 5 years.

2. She has been teaching/has taught at this school for twenty years.

3. David has been painting/has painted in his studio since 10 o’clock.

4. Mary and Sam have collected/ have been collecting stamps for 3 years.

5. Their parents have been/have being friends since their childhood.

6. Dave has been/ has been being a student for 2 years.