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2011-09-15 14:23:00   来源：网络整理    双击单词自动翻译

　　4.　　 Most consumers do not get much use out of the sports equipment they purchase. For example, seventeen percent of the adults in the United States own jogging shoes, but only forty-five percent of the owners jog more than once a year, and only seventeen percent jog more than once a week.Which of the following, if true, casts most doubt on the claim that most consumers get little use out of the sports equipment they purchase?

　　(A) Joggers are most susceptible to sports injuries during the first six months in which they jog.

　　(B) Joggers often exaggerate the frequency with which they jog in surveys designed to elicit such information.

　　(C) Many consumers purchase jogging shoes for use in activities other than jogging.

　　(D) Consumers who take up jogging often purchase an athletic shoe that can be used in other sports.

　　(E) Joggers who jog more than once a week are often active participants in other sports as well.

　　5.　　 Two decades after the Emerald River Dam was built, none of the eight fish species native to the Emerald River was still reproducing adequately in the river below the dam. Since the dam reduced the annual range of water temperature in the river below the dam from 50 de美国GREes to 6 de美国GREes, scientists have hypothesized that sharply rising water temperatures must be involved in signaling the native species to begin the reproductive cycle.Which of the following statements, if true, would most strengthen the scientists’ hypothesis?

　　(A) The native fish species were still able to reproduce only in side streams of the river below the dam where the annual temperature range remains approximately 50 de美国GREes.

　　(B) Before the dam was built, the Emerald River annually overflowed its banks, creating backwaters that were critical breeding areas for the native species of fish.

　　(C) The lowest recorded temperature of the Emerald River before the dam was built was 34 de美国GREes, whereas the lowest recorded temperature of the river after the dam was built has been 43 de美国GREes.

　　(D) Nonnative species of fish, introduced into the Emerald River after the dam was built, have begun competing with the declining native fish species for food and space.

　　(E) Five of the fish species native to the Emerald River are not native to any other river in North America.