问题补充:
单选题Asmoreandmorecarsareproducedandused,sothe_____fromtheirexhaust-pipescontainsanevenlargervolumeofpoisonousgas.A.exposureB.distributionC.expansionD.emission
答案:
D解析emission散发物,发射。exposure(to)暴露于:They believe that their health problems are the result of years of exposure to fine cotton dust.(他们认为,他们的健康问题是多年来暴露于棉花粉尘所致。)expansion膨胀,扩大;Heat causes the expansion of gas.本题译文:正如汽车的生产和使用越来越多一样,汽车的排气管的散发物内所含的有毒气体量也在增加。