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 объясните )))