12. They have played football for an hour.
13. How about using public buses instead of motorbikes?
14. He was pleased to get a good job.
15. He works well.
16. Since Tom was careless, he lost the game.
17. Don't forget to check your flight number.
18. Mr Ha wishes she had gone abroad.
19. Our teeth should be brushed carefully after meals.
20. I haven't written to him for 2 years.
