According to the passage the outbreak of deng
问题详情
According to the passage, the outbreak of dengue hemorrhagic fever in the 1950’s occurred for which of the following reasons？
A．The mosquito Aedes aegypti was newly introduced into Asia.
B．The mosquito Aedes aegypti became more numerous.
C．The mosquito Aedes albopictus became infected with the dengue virus.
D．Individuals who would normally acquire immunity to the dengue virus as infants were not infected until later in life.
E．More people began to visit and inhabit areas in which mosquitos live and breed.请帮忙给出正确答案和分析，谢谢！
参考答案
正确答案：B
解析：ThebestanswerisB.Lines22-26ofthepassagestatethatthedenguehemorrhagicfeveroutbreakoccurredwhenAedesaegyptibegantoproliferateasaresultofecologicalchanges.ChoiceAisincorrectbecausethepassageimpliesthatthemosquitowasalreadypresentinAsiainthe1950’s.ChoiceCcanbeeliminatedbecausethe1950’sepidemicisattributedbytheauthortoAedesaegypti,notAedesalbopictus.ChoicesDandEsuggestpossibilityiesmentionedinthepassageascausesforepidemicsofotherdiseasesbutnotofdenguehemorrhagicfever.
