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SECTION B SKIMMING AND SCANNING
In this section there are five passages with a total of ten multiple-choice questions. Skim or scan them as required and then select your answers to the questions.
TEXT F First read the following questions. 81. According to the passage, the canals allowed _____. A. the prevention of floods B. seawater to enter farmlands C. seawater to drain from the land D. the limestone to be exposed to air 82. In their nurseries, Tortugas shrimp require _____. A. rapidly moving water B. a high, steady water temperature C. a heavy concentration of salt water D. some fresh water mixed with the salt water Now read Text F quickly and select your answers. The record of peoples manipulation of nature in the Florida Everglades is replete with examples of remedies that were never fully analyzed before they were applied —— remedies that inevitably turned out to be more disastrous than the troubles they were intended to cure. It was peoples judgment, for example, that the rich muck of South Florida was going to waste under waste; so people drained off the water only to discover that muck, exposed to the heat of the sun, oxidizes into thin air. In some agricultural districts now as much as 40 percent of the organic soils are gone. Some farmers will be ploughing limestone by the year 2000. But they wont be raising any crops. Similarly, drainage undertaken to increase food production in one area has inhibited productivity in another; in periods of drought, the long canals became arms of the sea and salt water intruded on the land. In 1945, salinity in the soil killed off 18,000 acres of vegetables in southeast Dade country. Now increasing salinity in Florida Bay, caused by the decreasing outflow of fresh water from the Everglades, threatens the natural offshore nursery ground of the Tortugas shrimp and a 20 million annual commercial fishery.
81. According to the passage, the canals allowed _____.
A) the prevention of floods
B) seawater to enter farmlands
C) seawater to drain from the land
D) the limestone to be exposed to air
82. In their nurseries, Tortugas shrimp require _____.
A) rapidly moving water
B) a high, steady water temperature
C) a heavy concentration of salt water
D) some fresh water mixed with the salt water