1) I have to exchange our tickets. 2) I had to exchange our tickets. 3) I have to exchange our tickets. 4) I have to exchange our tickets a day from two to three in the afternoon. 5) The police must win public confidence. 6) Yesterday we had to go on a business trip. 7) The plane was supposed to take off on schedule. 8) We will have to spend the night at the airport. 9) No one must know of my secret. 11) No one had to know my secret. 12) We were supposed to meet at noon yesterday, but we have not met. 13) Our colleague is not necessary to speak at tomorrow's conference. 14) Our colleague was supposed to produce a report, but he did not have to act in the negotiations. 15) Our partners must inform us of their decision tomorrow.
Объяснение:
1. I have to exchange our airline tickets.
2. I had to exchange our airline tickets.
3. I'll have to exchange our airline tickets.
4. I have to exchange our airline tickets today between 2:00 and 3:00.
5. The police must gain public trust.
6. Yesterday we had to go on a business trip.
7. The plane was supposed to take off exactly on schedule.
8. We have to spend the night at the airport.
9. No one can know my secret.
10. No one was supposed to know my secret.
11. We were supposed to meet last night at noon, but we didn't.
12. Members of the British Parliament are prohibited from entering the House in armour.
13. Our colleague does not need to speak at tomorrow's conference.
14. Our colleague was to prepare a report, but he does not have to speak at the negotiations.
15. Our partners should inform us of their decision tomorrow.
2) aren't they?
3) didn't he?
4) won't she?
5)don't they?
6) aren't there?