Раскройте скобки, употребляя глаголы в past perfect continuous active. 1) they (to keep) silence for some time when somebody entered the room. 2) she (to lie) there for two hours when we found her. 3) it (to rain) hard for 3 weeks until the weather changed. 4) the four of them joined mark, who (not, to work) for half an hour. 5) i (to stand) at the bar for 40 minutes when my acquaintance came up. 6) she (to wait) for him all the morning when he appeared? 7) my brother (to volunteer) there for a year before he entered the university?

1) They had been keeping silence for some time when somebody entered the room.
2) She had been lying there for two hours when we found her.
3) It had been raining hard for 3 weeks until the weather changed.
4) The four of them joined Mark, who had not been working for half an hour. 5) I had been standing at the bar for 40 minutes when my acquaintance came up.
6) Had she been waiting for him all the morning when he appeared?
7) Had my brother been volunteering there for a year before he entered the university?