Respuesta:
1) I wasn't reading the book.
2) You weren't working last night.
3) She wasn't in Miami last August.
4) He wasn't a good student when he was in College.
5) We weren't dancing together.
6) You weren't living in a big house.
7) They weren't celebrating their graduation.
8) It wasn't rainning yesterday.
9) Mark wasn't sitting in front of me.
10) Rose wasn't my best friend.