16. Adolescence are usually a bit tense with emotional changes and don’t know how _____ them. A. overcome B. to overcome C. overcoming D. for overcoming 17. His parents have too _____ expectations for him and want him to be the best student in his class. A. big B. small C. high D. low 18. She cried a lot when she knew she was _____ out by her classmates. A. stayed B. put C. left D. came 19. My parents asked me to find out _____ it gave you so much trouble. A. what B. which C. why D. where 20. About 85 per cent of city _____ breathe heavily polluted air. A. villagers B. livers C. dwellers D. members