21. I don't know where to go now. Pass me the ________, please.

      A. backpack                B. map                         C. sleeping bag            D. sun hat

22. It can be very dark inside a ________.

      A. coat                        B. cave                        C. beach                      D. coast

23. Co To is a(n) ________ in Quang Ninh province.

      A. forest                      B. rainforest                C. island                      D. freshwater lake

24. Can anyone swim across this ________ within 30 minutes?

      A. valley                      B. river                        C. waterfall                 D. cuisine

25. Can you name some famous tourist ________ in Vietnam?

      A. attractions              B. nature                     C. cuisine                    D. travel items

26. Which of the following is a ________ river?

      A. mount                     B. landscape                C. boat                        D. man-made