past continuous vs. past simple

Hi, this is an exercise from Oxford English Grammar Course. Choose the correct tense (the underlined phrases are correct according to the Key in the book). I can´t help thinking, that in sentences 3 and 5, and probably even 11 past continuous is possible, so both options are correct as past continuous is often used with phrases like "all day/all morning/all afternoon/ all Saturday". And I often see present continous in the context of "What are you studying? I am studying law." So in sentence 11 it would be just a past equivalent. Or am I wrong?
Thank you very much for your clarification.

1. I lived/was living in France for eight years.
2. Sue lived/was living in France when her uncle died.
3. We watched/were watching TV all evening..
4. Matt watched/was watching TV when Anita came in.
5. My father worked/was working hard all his life.
6. They got married while they studied/were studying at London university.
7. At 6.15, when you phoned, I had/was having a shower.
8. Yesterday we drove/were driving from Oxford to Edinburgh and back.
9. It was a nice evening, so she walked/was walking home from work.
10. I met Sylvie while I worked/was working in Japan.
11. At university I studied/was studying physics.
12. When I last saw him he talked/was talking to a policeman.