阅读理解阅读理解
阅读下列短文,然后从各题所给的四个选项(A、B、C和D)中,选出最佳选项。
Whydoescreamgobadfasterthanbutter?Someresearchersthinktheyhavetheanswer,anditcomesdowntothestructure(结构)ofthefood,notitschemicalcomposition(成分)afindingthatcouldhelpbreakawayfromsomechemicals.Creamandbuttercontainprettymuchthesamethings,sowhycreamshouldgobadmuchfasterhasbeenaproblem.Botharesmallglobules(小球)ofoneliquidspreadthroughoutanother.Thedifferenceliesinwhat'sintheglobulesandwhat'sinthesurroundingliquid,saysBrocklehurst,wholedtheresearch.Incream,fattyglobulesdriftaboutinaseaofwater.Inbutter,globulesofawateryroadarelockedawayinaseaoffat.Thebacteria(细菌)whichmakethefoodgobadprefertoliveinthewateryareasofthemixture.“Thismeansthatincream,thebacteriaarefreetogrowthroughoutthemixture,”hesays.Wheninbutter,thebacteriaarelockedawayinlockedplacesburieddeepintheseaoffat.Trappedinthisway,thosecoloniescannotspreadandrapidlyrunout.Theyalsoslowlypoisonthemselveswiththeirwasteproducts.“Inbutter,yougetaself-limitingsystemwhichstopsthebacteriagrowing,”saysBrocklehurst.Theresearchersarealreadyworkingwithfoodcompanieseagertoseeiftheirproductscanbemadetostandbacterialattackthroughchangesofthefoods'structure.Brocklehurstbelievesitwillbepossibletomakesomethingusedinsaladcreamforinstance,morelikethatinbutter.Thekeywillbetodothiswhilekeepingthesaladcreamliquidandnotturningitintoasolidstate.
1.Accordingtotheresearchers,creamgoesbadfasterthanbutterbecausebacteria________.
[]
A.arestrongerincream
B.increasetheirnumbermoreeasilyincreamthaninbutter
C.liveonlessfatincreamthaninbutter
D.producelesswasteincreamthaninbutter
2.AccordingtoBrocklehurst,wecankeepcreamfreshby________.
[]
[]
邮箱:联系方式: