阅读理解阅读理解。Todayultrasonic(超声的)wavesarebeingputtoworkinlaboratoriesandfactories．Ifanultrasoundgeneratorisplacedinaliquidthewavesmovethe|小学英语问答-字典翻译问答网

问题标题：

阅读理解阅读理解。Todayultrasonic(超声的)wavesarebeingputtoworkinlaboratoriesandfactories．Ifanultrasoundgeneratorisplacedinaliquidthewavesmovethe

问题描述：

(1)

阅读理解

阅读理解。

Todayultrasonic(超声的)wavesarebeingputtoworkinlaboratoriesandfactories．Ifanultrasoundgeneratorisplacedinaliquidthewavesmovetheliquidbackandforthhundredsofthousandsoftimeseachsecond．Thiscausesmaterialstomixquicklyortodissolve(使分解，使溶解)inliquids．Paintmanufacturers(制造商)useultrasoundtodoabetterjobofblendingcolors．Thecompaniesthatmakefilmforyourcamerafindthatmixingchemicalsbytheuseofsoundwaveswillproduceamoresensitivefilm．

Thenewlightweight(轻量的)typeofwashingmachineusesultrasonicwavestogetclothesclean．Itsspecialultrasoundgeneratorisputintoapailofsoapywatercontainingthesoiledclothes．Thesoundwavesdrivethesoapywaterbackandforththroughtheclothsofastthateverythingissoonclean．Thereisalsoanewkindofdishwasherthatworksinmuchthesameway．

Ultrasonicwavescanshakealiquidsofastthattinyholesformallthroughit．Theliquidisactuallytornapartbythisaction．Almostassoonastheseholesaremadetheyfalltogetheragain．Theresultisapowerfulpoundingaction．Inthedairyindustrythisisusedforthedoublepurposeofmakinghomogenized(使均匀，使匀质)milkandsterilizing(使无菌)itatthesametime．Ifyoulookatsomerawmilkwithamicroscopeyoufindthatitismadeupoflittledropsofbutterfatfloatingaroundinawateryliquid．Inordertomakemilkeasiertodigestthesefatdroplets(微粒)maybebrokenupbyforcingthemilkthroughverysmallopenings．Theresultiscalledhomogenizedmilk．Whentheultrasonicmethodisusedthesoundwavesnotonlybreakupthedropletsbutalsokillthegermsinthemilkbypoundingthemtopieces．

Whydoesapaintmanufactureruseultrasoundtodoabetterjobofblendingcolors?

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A．

Becauseitischeaptouseultrasoundtoblendcolors．

B．

Becausethewavesmovetheliquidsoquicklythatitcanmakemateri

任晓林回答：

　　答案：1．B;2．D;3．C;4．B;

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