IV.
16. The weather is very hot in desert (c). You can see camels and rattlesnakes easily there.
17. Cam Ly waterfall (b) in Lam Dong province attracts many tourists to visit each year.
18. My sister had a headache yesterday when she returned from her camping. My mother gave her some painkillers (a) to reduce it.
19. My brother and I wear walking boots (a) to move conveniently when go hiking in the mountain.
20. We brought a torch (d) to look around when we move in the jungle in the dark.
21. I had an occasion to come to visit Ngu Hanh Son. It's a mountain mount (c) in Da Nang.
22. Those islands in Nha Trang are named by (d) some interesting animals such as monkeys or swiftlets.
23. It is essential (c) to check your luggage carefully when you travel somewhere by plane.
24. Ba Be Lake in Bac Kan is the largest (a) natural lake in Viet Nam.
25. Many people say that Nile is the deepest (a) river in the world.
26. I think Nam is one of the best (a) your guides in this company.
27. What is the highest (b) mountain in Viet Nam?- I think it's Fansipan.
28. We must (b) get up early to be at the campsite in time.
29. You musn't (c) throw the rubbish into the West Lake.
30. We can hold a party tonight but we mustn't (d) some loud noises affecting our neighbors