passage 6
water problems in the future will become more intense and more complex. our increasing population will tremendously increase urban wastes, primarily sewage. on the other hand, increasing demands for water will decrease substantially the amount of water available for diluting wastes. rapidly expanding industries which involve more and more complex chemical processes will produce larger volumes of liquid wastes, and many of these will contain chemicals which are noxious. to feed our rapidly expanding population, agriculture will have to be intensified. this will involve ever increasing quantities of agricultural chemicals. from this, it is apparent that drastic steps must be taken immediately to develop corrective measures for the pollution problem.
there are two ways by which this pollution problem can be dwindled. the first relates to the treatment of wastes to decrease their pollution haz3rd. this involves the processing of solid wastes "prior to" disposal and the treatment of liquid wastes, or effluents, to permit the reuse of the water or minimize pollution upon final disposal .
a second approach is to develop an economic use for all or a part of the wastes. farm manure is spread in fields as a nutrient or organic supplement. effluents from sewage disposal plants are used in some areas both for irrigation and for the nutrients contained.
effluents from other processing plants may also be used as a supplemental source of water. many industries, such as meat and poultry processing plants, are currently converting former w3ste products into marketable byproducts. other industries are exploring potential economic uses for their waste products.
56. the purpose of this passage is ________.
a. to acquaint the reader with water pollution problems
b. to alert the reader to the dwindling water supply
c. to explain industrial uses of water
d. to demonstrate various measures to solve the pollution problem
57. which of the following points is not included in the passage?
a. diluting wastes needs a certain amount of water.
b. demands for water will go up along with the expanding population .
c. intensive cultivation of land require more and more chemicals.
d. industrial development includes the simplification of complex chemical processes.
58. the reader can conclude that _________.
a. countries of the world will work together on pollution problems
b. some industries are now making economic use of liquid waste
c. byproducts from wastes lead to a more prosperous marketplace
d. science is making great progress in increasing water supplies
59. the author gives substance to the passage through the use of________.
a. interviews with authorities in the field of water controls
b. definitions which clarify important terms
c. opinions and personal observations
d. strong arguments and persuasions
60. the words "prior to"(para. 2)probably man________.
a. during b. before
c. after d. beyond