Viết lại các câu sau đây sao cho nghĩa không đổi

1. We last saw each other when we left university
--> We haven't ................
2. It was the fog that caused the traffic problem

--> If it ...............
3. Success depends on hard work
--> The harder ..............
4. Jonh thought it was too difficult for him to finish the job by lunchtime

--> Jonh found ................
5. The train had hardly left the railway station when a big problem occurred

--> No sooner .................