Choose the correct form of the verb.
1. I … him before we met at the concert.
a) didn't see b) wasn't seeing c) hadn't seen
2. When mother came home, the children … the soup.
a) ate b) were eating c) had eaten
3. The telegram … some minutes after he had left.
a) came b) was coming c) had come
4. While we … the road I saw Victor.
a) crossed b) were crossing c) had crossed
5. When … your sister … to London?
a) did … go b) was … going c) had gone