Polyester(聚酯)isnowbeingusedforbottles.ICI,thechemicalsandplasticscompany,believesthatitisnowbeginningtobreakthegripofglassonthebottlebusinessandthustakeadvantageofthishugemarket. Alltheplasticsmanufacturershavebeenexperiencinghardtimesastheirtraditionalproductshavebeendoingbadlyworld-wideforthelastfewyears.Between1982and1984thePlasticsDivisionofICIhadlostahundredandtwentymilliondollars,andtheyfeltthatthemosthopefulnewmarketwasinpackaging,bottlesandcans. Since1982ithasopenedthreenewfactoriesproducing"Melinar",therawmaterialfrownwhichhighqualitypolyesterbottlesaremade. Thepolyesterbottlewasborninthe1970s,whensoftdrinkscompanieslikeCocaColastartedsellingtheirdrinksingianttwo-litercontainers.Becauseofthebuild-upofthepressureofgasintheselargecontainers,glasswasunsuitable.NorwasPVC,theplasticwhichhadbeenusedforbottlessincethe1960s,suitablefordrinkswithgasinthem.Anewplastichadtobemade. Glassisstillcheaperforthesmallerbottlesandwillcontinuetobeso,unlessoilandplasticbecomemuchcheaper,butplasticdoeswellforthelargersizes. Polyesterbottlesarevirtuallyunbreakable.Themanufacturersclaimtheyarealsolighter,lessnoisywhenbeinghandled,andcanbereused.Shopkeepersandotherbusinesspeopleareunlikelytoobjecttoachangefromglasstopolyester,sincethesebottlesmeanfewbreakages,whicharecostlyandtime-consuming.Thepublic,though,havebeenmoredifficulttopersuade.ICI'scommercialdepartmentisdevelopingdifferentbottleswithinterestingshapes,totryandmake themvisuallymoreattractivetothepublic. Thenextstepcouldbetodevelopaplasticwhichcouldreplacetinsforfood.Theproblemhereisthehightemperaturesnecessaryforcookingthefoodinthecontainer. ?Plasticsofvariouskindshavebeenusedformakingbottles__________.
A.since 1982
B.since the 1970s but only for large bottles
C.since the 1960s but not for liquids with gas in them
D.since companies like Coca Cola first tried them
正确答案是C