Cho tam giác ABC, một đường thẳng song song với BC cắt AB,AC lần lượt tại D,E và cắt đường thẳng kẻ từ C song song với AB tại F. Gọi giao điểm AC và BF là S

a, CMinh: AB.CE=AC.CF

b,CMinh:SC²=SA.SE

1. What you (do) if I hadn’t lend you the money?

2. If you had asked me for ticket, I (get) you some tickets.

3. I (not marry) him If I had known what he was like.

4. I wouldn’t have hired a car if I (know) how expensive it was.

5. If we (go) to the cinema earlier, we wouldn’t have missed the start of the film.

6. If I had been born a year earlier, I (have) to do military service.

7. If you (ask) me , I would have lend you my car.

8. If I had gone to university, I (get) a better job.

9. I (not go) out yesterday , If you had asked me not to.

10. I could have given you a lift if my car (not break) down.

11. I (not go) to Britain if I had known what was going to happen.

12. I would have stay longer if he( want) me to.

13. I (not come) to this school if I had known it was like.

14. We would have gone to his party if we be able to find a baby – sister.

15. . I (visit ) you in the hospital if I had known you were there