12. The flight may be cancelled if the fog (get)thick.
13. Ifthe milkman (come) tell him to leave two pints.
14. I(call) the office if I were you.
15. Someone (sit) on your glasses if you leave them there.
16. You would hear my explanation if you (not talk)go much.
17. What 1 (do) if I hear the burglar alarm?

18. If you (read)the instructions carefully, you wouldn't have answered the wrong question.
19. If Mel (ask)her teacher, he'd have answered her questions
20. I would repair the roof myself if I (have)a long ladder.
21. Unless they turn that radio off, I (go)mad
22. If you were made redundant, what you (do)?
23. We'll have a long way to ưalk if we (run) out of petrol here.

1. If we meet at 9:30, we (have)plenty of time.
2. If you (find)a skeleton in the cellar, don't mention it to anyone.
4. If you pass your examination, we (have)a celebratipn.

5. Lisa would find the milk if she (look)for it in the fridge.
6. What (happen)if I press this button?
7. The door will be unlocked if you (press)the green button.
8. I should have voted for her if I (have)a vote then.
9. If you go to Paris, where you (stay)?
10. If you (swim) in this lake, you'll shiver from cold.
11. If someone offered to buy you one of those rings, which you (choose)

cho \(\frac{1}{2}\)(o) đường kính AB, vẽ tiếp Ax, By. trên nửa đường tròn lấy C bất kì, qua C vẽ tiếp tuyến d của đường tròn, d cắt Ax tai E, By tại F (vẽ cả hình cho mình nha)
a, CM: 4điểm A, E, C, O ϵ 1 đường tròn
b, CM: EF = AE + BF
c, CM: góc EOF = 90^o