15.2
2. I`d never seen her before.
3.He`d never played tennis before.
4. We`d never been there before.
15.3
1.So we called the police.
2. ...but there was no answer. She had gone out.
3. ...he had just come back from holiday. He looked very well.
4. Yesterday Kevin got a phone call from Sally. He was very surprised. He had sent her lots of emails, but she had never replied to them.
6.2
2. The doorbell rang, while I was taking a shower.
3. We saw an accident while we were crossing the street.
4. Ann fell asleep while she was reading her favorite book.
5. The television was on, but nobody was watching.