A. by bike B. volunteer C. mask D. quarrel A. dream about B. Olympic Games C. goodwill D. treat A. silly B. interval C. manufacture D. able A. connect B. look out for C. maturity D. clarify A. watertight B. operate C. guilty D. South American A. by means of B. consist C. fry D. dial A. first aid B. hundred C. back to back D. roof A. settlement B. clue C. faulty D. second floor A. ring off B. prepare for C. utilitarian D. throat A. photographer B. revolution C. envelope D. at the moment