1. They are playing chess right now. They have been playing chess since lunch.

2. entered, wereplaying

3. has been working

4. have been working

5. amgoing, have always wanted

6. have been, visited

7. are waiting, have been wating

8. have never been there.

9. The tsarina fell ill in 1560.

10. I was watching, switched the television itself off.

11. The tsar tried

12. entered, were sitiing, was looking, didn't see, turned

13. What does "revenue" mean?

14. I have passed

15. Oleg does not go