Before:
1.Before I went to bed last night,I had read some books.
2.Before I watched TV,I had finished my homework.
3.Before the police got there,the murder had run away.
4.Before I arrived at the airport,he had left.
5.Before you knew the truth,I had known that.
By the time:
1.By the time that the teacher explained this question to us,I had already sloved it.
2.By the time you arrived here,he had left.
3.By the time they went to home,the fire had been put off.
4.By the time everyone knew the truth,I had admitted my mistake to my teacher.
5.By the time we arrived at the cinema,the film had started.
after:
1.After you knew that,it had been too late.
2.After they found the key to the door,the owner of the house had been back.
3.After I realized its importance,it had been too late.
4.After we finished our work,it had been 11 o'clock in the night.
5.After she told me to throw away those clothes,I had already washed them.
