Выбрать правильный вариант 1. What are they doing/do they do at

Выбрать правильный вариант
1. What are they doing/do they do at this moment?
2. When I came in, she was reading/she read a book.
3. Liz travelled/has travelled to China last year.
4. By 8 o'clock yesterday David had done/was doing his homework.
5. They have swim/have been swimming for two hours already.
6. This train leaves/is leaving at 5 p.m.
7. The exam started/had started by the time I got to class.
8. Danny won't phone us until he has/has had more details.