4) 1-a
2-c
3-c
4-a
5-b
6-b
5)1-were, would visit
2-had laid, wouldn't have been
3-would behave, took
1-she said that somebody had stolen her bag in the shop.
2-he said that he couldn't move the piano alone.
3-the students said that they were very sorry for coming so late.
6) 1-ambitious
2-independence
3-exploration