GRE阅读逻辑练习题（9）_GRE阅读

GRE阅读逻辑练习题（9）

　　 Because todays pesticides typically have more specific application conditions than did pesticides in use 40 years ago, todays farmers observe their fields more closely than did farmers 40 years ago.

　　 Certain pest-control methods that some farmers use today do not involve the use of chemical pesticides but are just as effective in eliminating insect pests as those that do.

　　 Forty years ago, much less was known about the effects of pesticides on humans and other mammalian species than is now known.

　　9.Authorities in California required drivers to use their headlights on a certain road during the daytime as well as at night and found that annual accident rates on the road fell 15 percent from the previous level. They concluded that applying the daytime rule statewide would lead to a similar reduction in accidents.

　　Which of the following, if true, most strengthens the authorities argument?

　　 Because an alternate route became available, the volume of traffic on the test road decreased during the test period.

　　 Drivers were informed of the requirement to use their headlights on the test road by means of a series of three conspicuous signs in each direction of travel.

　　 Under certain conditions, among them fog and heavy rain, most drivers in California already use their headlights during the daytime.

　　 Full-scale application of the daytime rule would cause headlight bulbs to burn out sooner than they currently do and thus to require more frequent replacement.