Complete the sentences:
1. Mark and Liz are married. They ... have been married for 5 years.
2. David has wathced TV ... 5 o'clock.
3. I have been there ... 5 days.
4. Tom has had the same job ... 20 years.
5. How long ... there?
6. I have know Ann ... we were at school.
7. I have never ... a horse.