1. We/to wait/outdoors/for twenty minutes/before/he/opened the door. 2. What/Sally/to cook/when/you/came/home/ yesterday? 3. How long/you/to repair/your car/before/Nick/ started/to help/you? 4. Sarah/to collect/dolls/since/she/ was/a girl. 5. Where/they/to come/f rom/when/you/met/them/ yesterday? 6. Who/to sing/karaoke/all the evening/yesterday? 7. Greg/to study/for his final exams/all last month? 8. They/ to drive/for five hours/when/they/ran out of petrol. 9. Tony/ to sleep/for an hour/before/you/woke/him up. 10. Our chief/ to discuss/some affairs/with our business partners/for two hours/last Wednesday.
Ответы на вопрос
We waited outdoors for twenty minutes before he opened the door.
What did Sally cook when you came home yesterday?
How long did you repair your car before Nick started to help you?
Sarah has been collecting dolls since she was a girl.
Where did they come from when you met them yesterday?
Who sang karaoke all evening yesterday?
Did Greg study for his final exams all last month?
They were driving for five hours when they ran out of petrol.
Tony was sleeping for an hour before you woke him up.
Our chief discussed some affairs with our business partners for two hours last Wednesday.
Ответ:
We had been waiting outdoors for twenty minutes before he opened the door.
What was Sally cooking when you came home yesterday? or What had Sally been cooking when you came home yesterday?
How long had you been repairing your car before Nick started to help you?
Sarah had been collecting dolls since she was a girl.
Where were they coming from when you met them yesterday? or Where had they been coming from when you met them yesterday?
Who was singing karaoke all evening yesterday? or Who had been singing karaoke all evening yesterday?
Had Greg been studying for his final exams all last month?
They had been driving for five hours when they ran out of petrol.
Tony had been sleeping for an hour before you woke him up.
Our chief had been discussing some affairs with our business partners for two hours last Wednesday.
Объяснение:
во всех предложения преимущественно употребляется Past Perfect Continuous , однако во 2м,5м,6м также может быть употреблён Past Continuous -всё зависит от контекста.