[简答]  二、阅读理解：阅读下面的短文，根据文章内容从A、B、C三个选项中选出一个最佳选项。（教材课文原文）2050,theworld'spopulationtoriseto9billionfromjustover7billioncurrently.Proponentsofgeneticallymodifiedfoodssaytheyaresafeandcanboostharvestsinbadconditionsbyprotectingagainstpests,weedsanddrought.This,theyargue,willbeessentialtomeetingtheneedsofaboomingpopulationindecadestocomeandavoidingstarvation.DougGurian-Sherman,seniorscientistforthefoodandenvironmentprogramattheUnionofConcernedScientists,anadvocacygroup,saidgeneticengineeringforinsectresistancehasprovidedonlyamodestincreaseinyieldssincethe1990sanddrought-resistantstrainshaveonlyreducedlossesfromdrought.