专项提能计划——阅读理解(三)科普类(2011·高考陕西卷·D)Eversincetheywerefirstputonthemarketintheearly1990s,geneticallymodified(GM,转基因)foodshavebeenincreasinglydevelopedandmarketedinmanycountriesintheworld,mainlyonthebasisoftheirpromisetoendtheworldwidefoodcrisis
ButcanGMtechnologysolveworldhungerproblems
Evenifitwould,isitthebestsolution
Despitewhatitpromises,GMtechnologyactuallyhasnotincreasedtheproductionpotential(潜力)ofanycrop
Infact,studiesshowthatthemostwidelygrownGMcrop,GMsoybeans,hassufferedreducedproductivity
Forinstance,areportthatanalysednearlytwodecadesofresearchonmajorGMfoodcropsshowsthatGMengineeringhasfailedtosignificantlyincreaseUScropproduction
Somethingelse,however,hasbeenontherise
WhileGMseedsareexpensive,GMcompaniestellfarmersthattheywillmakegoodprofitsbysavingmoneyonpesticides(杀虫剂).Onthecontra