問題詳情

四、閱讀測驗【請在下列各題中選出最適當的答案】第一篇：Infecting mosquitoes with a bacterium is a roundabout way to fight dengue fever, but scientists are workinghard on it because otherwise the options are few. Dengue, nicknamed “breakbone fever” for the crippling pain itcauses, infects 390 million people every year. Because there is no cure or treatment, the chief strategy has been toattack Aedes aegypti, the mosquito that transmits the virus. Yet common insecticides such as temephos have lostmuch of their effectiveness as mosquitoes have developed resistance. Bed nets are almost useless, too, because
(A)aegypti typically feed during the day. At present, one of the most promising tools for halting the spread ofdengue—and perhaps malaria and other mosquito-borne illnesses—appears to be spreading Wolbachia among wildmosquitoes.Wolbachia is not an obvious choice as a dengue fighter. It does not naturally occur in the mosquitoes that mostoften transmit dengue. Scientists actually have had to infect those mosquitoes artificially, in the laboratory. In otherwords, they use Wolbachia to immunize the mosquitoes against dengue and then set them loose in the wild, wherethose mosquitoes will pass the bacterium to their offspring. Wolbachia is largely benign for mosquitoes and theenvironment, although it may reduce the insects’ egg production. But the potential benefits for humans are clear: ifmosquitoes infected with Wolbachia become predominant in the wild, scientists expect dengue infection ratesamong people to drop.
51. What is this passage mainly about?
(A) How dengue fever spreads among humans.
(B) How a potential cure for dengue fever is being developed.
(C) How mosquitoes can be killed effectively.
(D) How a bacterium may help us fight dengue fever.

參考答案

答案：D
難度：困難0.39759
統計：A(10),B(23),C(15),D(33),E(0)

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