13. The __________________ they made at school will last through their life. (friend)
14. Their uncle did some __________________ in Rome last year. (sightseer)
15. The students have done the exercises __________________. (easy)
16. Liz found the journey __________________. (enjoy)
17. Tuan is one of the most famous___________________in the world. (environment)
18. The air is__________________polluted by exhaust fumes me from cars. (serious)
19. Tet is one of the most important ________________for Vietnamese people . ( celebrate )
26. There have been more floods because of _________________ . ( forest )
27. Jogging is a very _____________form of exercise . ( energy )
28. I think the careless drivers should be fined ___________. ( heavy )
29. That program is very __________. None of us likes it . ( bore )
30. Air ____________can cause a lot of respiratory problems . ( pollute )