Choose the word (A, B, C or D) that best fits the blank space in the following passage. Many rivers and lakes around the world are polluted. The (17)_________ of waste materials by factories and households cause pollution to rivers and lakes. The Rhine Rivers in Europe and the Great Lakes in North America are good (18)_________ of rivers and lakes that are polluted. Their water (19)_________ be drunk. The same thing is happening to the sea. In one instance, certain factories in Japan dumped industrial waste (20)_________ the sea. Many people (21)_________ from lead or mercury poisoning after eating fish caught in (22)_________ polluted waters. 17. A. use B. discharge C. recycle D. supply 18. A. examples B. models C. samples D. reflection 19. A. will B. have not C. cannot D. are not 20. A. in B. to C. into D. at 21. A. prevented B. attacked C. affected D. suffered 22. A. such B. so C. very D. too