Many cities have a serious pollution problem. Motor vehicles, factories, and other(1)_sources____create so much air pollution that it may hang in the air like (2)__dirty____ fog. Air pollution (3)__threatens__the health of the people who live in cities. City (4)___wastes___ cause water pollution when they are poured into These wastes kill fish and make some (5)__pollution__ unfit for wimming. In addition, many large cities have difficulty (6)____disposing__ of their garbage. The amount of (7) __products____grows each year, but places to put it are quickly filling up.
Citizens, governments, industries, scientists, and business people must work together to gradually reduce (8) ___gargage___For example most cities have introduced (9)__recycling____ programs, which cut down on garbage and the space needed to store it. dents separate recyclable products from garbage, and city governments provide drop-off cites or pick up the (10)______ from homes.