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14. You shouldn't criticize him in front of many people.
15. He wishes he hadn't said those terrible things.
16. He must have done it on purpose.
17. You don't need to pay too much attention to your appearance.
18. Should nuclear tests not stop, life on earth will be destroyed.
19. She is the most kind-hearted girl that I have ever met.
20. Lan's house is the same size as An's house.
21. Radio was invented by Marconi about a hundred years ago.
22. My father wishes he could speak English.
23. Liz asked me if those clothes belonged to me.

24. Did you use to wear jeans when you were young?
25. This is the first time we have been to Viet's native village.
26. Unless someone puts the coal in, the fire will go out.