IV. Give the correct form of the words in the brackets. Question 16. The lecture is about the ……………….. of the world heritage sites. (preserve) Question 17. The tour of cave system is the main ………. for tourists in Phong Nha Ke Bang National Park. (attract) Question 18. Scholars believe that there are still relics buried under the tomb and awaiting ……… (excavate) Question 19. New York city is facing with the problem of …………… electricity network. (age) Question 20. Cities will be ………………… and traffic will be heavy. (populatio Question 31. The building is the highest one in our city. It was destroyed in the earthquake. (using participle) ...................................... Question 32. The man is our English teacher. He talked to you yesterday. (using participle) ................................. Question 33. After she had read her book carefully, she did the exercises confidently. Having______________ Question 34. Lan had played truant for class. She was accused of it. Lan _______________ Question 35. Mai started studying her lesson since 7 o’clock. She’s still studying. (been) Mai ______________