Choose the right variant. When we came to the sports

Choose the right variant.
When we came to the sports ground they football.
a) played b) will play c) were playing
2. My father TV yesterday.
a) was watching b) watched c) has watched
3. While Jane a book, Susan was dancing.
a) was reading b) read c) is reading
4. Tom coffee while he was reading a newspaper.
a) drank b) was drinking c) were drinking
5. I a letter to my friend last week.
a) write b) wrote c) was writing

помогите и растолкуйте )))