22 B
23 C
24 C
25 B
III
1 Before we came, they had already left for England
2 Before she went to bed, she had done all her homework
3 After we had locked the door, we went out for a walk
4 After having turning off the washing machine, Sara cooked dinner
5 After having done his homework, David played football with his friends
6 Before Laura phoned Mark, he had already known the truth