Откройте скобки: 1. the lights (to go down) and it ( to be difficult to find the seats in the theatre hall. 2. we (to show) our tickets to the usher when the second bell (to ring). the perfomance (to start) in three minutes. 3. when the curtain (to go up), you can (to see) the scenery on the stage. 4. they (to discuss) the perfomance when they (to see) the actress who (to play) the leading role in the perfomance. 5. the afternoon perfomance at the theatre usually (to start) at one o'clock. (на завтра)

1. The lights had gone down and it was difficult to find the seats in the theatre hall.
2. We were showing our tickets to the usher when the second bell rang. The perfomance was to start in three minutes.
3. When the curtain goes up, you can see the scenery on the stage.
4. They were discussing the perfomance when they saw the actress who had played the leading role in the perfomance.
5. The afternoon perfomance at the theatre usually starts at one o'clock.

1. gone down was.
2. had shown rung. started
3. has gone up  see
4. were discussing saw. was playing
5. starts.
(PS за ошибки не отвечаю)