Question 15. [NB] Choose the best option A, B, C, or D to complete each sentence. If it rains, we ________ the match. A. cancel B. will cancel C. cancelled D. cancelling Question 16. [TH] Choose the best option A, B, C, or D to complete each sentence. Australia has the biggest _________ in the world. A. natural beauty B. puzzling games C. cattle station D. population Question 17. [TH] Choose the best option A, B, C, or D to complete each sentence. The USA has a population of about 304 million, and it’s the third _______ country in the world. A. smallest B. largest C. narrowest D. highest Question 18. [NB] Choose the best option A, B, C, or D to complete each sentence. If the factory __________ dumping poison into the lake, all the fish and other aquatic animals will die. A. will continue B. to continue C. continue D. continues Question 19. [NB] Choose the best option A, B, C, or D to complete each sentence. The woman sitting next to me on the plane was very nervous. She __________ before. A. hasn’t flown B. hadn’t flown C. didn’t fly D. doesn’t fly Question 20. [NB] Choose the best option A, B, C, or D to complete each sentence. Using ________ including Facebook, YouTube, etc as a means of communication has become very popular among young people. A. social media B. email C. letters D. telepathy Question 21. [TH] Choose the best option A, B, C, or D to complete each sentence. How many languages are _________ in China? A. speak B. speaking C. spoken D. speaker