I. Употребить Perfect, Pest или Future Perfect.

1. When we came into the hall the concert already (to finish).
2. We (to discuss) just the problems of social relations.
3. I (to graduate) from a college before I entered the Institute.
4. They (to construct) a great number of new buildings by the end of the year.
5. He apologized because he (to cause) so much trouble.
6. I hope I (to receive) a reply by tomorrow.
7. You ever (to visit) Great Britain?
8. This famous laboratory always (to play) an outstanding role in training physicists.
9. He remembered that he (to be) at that plant before.
10. I cannot deliver a lecture now as I (to leave) my papers at the office.