=>

1. When were Cathorine and Henry engaged?

2. I haven't seen him since I was a student.

3. Alan hasn't visited his parents for ages.

4. This will be the last time we see each other.

5. By the time he got to the station, the train had left.

6. It is ten years since the school was founded.

7. It was six months since she had a relapse.

8. The last time I went for a meal was two years ago.
9. This is the first time his authority has been challanged./This is the first time someone has challenged his authority.

`~rai~`

\(\text{1.When were  Catherine and Henry engagged?}\\\text{2.I haven't seen him since I was a student.}\\\text{3.Alan hasn't visited his parents for ages.}\\\text{4.This will be the last time we meet each other before I go.(không chắc lắm)}\\\text{5.By the time he got to the station,the train had left.}\\\text{6.It is ten years since the school was founded.}\\\text{7.It was six months since she last had a relapse.}\\\text{8.The last time I forwent a meal was two years ago.}\\\text{9.This is the first time his authority has been challenged.}\)