Twomindswithasinglethought!Theyoungfishermanisthinkingofawaytocrossthestreamwithoutgettinghis__1__wet.Theengineeristhinkingofa__2__togetautomobilesacrosstheriverwithoutgettingtheirwheelswet.Youknowthea

　　Twomindswithasinglethought!

　　Theyoungfishermanisthinkingofawaytocrossthestreamwithoutgettinghis__1__wet.Theengineeristhinkingofa__2__togetautomobilesacrosstheriverwithoutgettingtheirwheelswet.Youknowtheanswerto__3__problems：abridge.

　　Thefisherman'sbridgedoesn'ttake__4__tobuild.Justplaceaboardacrossthelittlestreamandyou__5__.Iftheboardisstrongenoughandifthefishermandoesn't__6__toomuch，allwillbewell.

　　Willtheengineer__7__thesamekindofbridge？Youknowhe__8__andyouknowwhy.Automobilesaremuchheavierthan__9__.Theriverismuch__10__thanthestream.Alongwoodbridgejustwon't__11__.Itisn'tstrongenough.Itwould__12__andbreakunderitsownweight.Thefisherman'sproblemisvery__13__.However，theengineer'sisnot.

　　Butdon't__14__sorryfortheengineer.Hedoesn'thaveto__15__theverybeginningwithalongboard.Peoplehavebeenthinkingaboutbridgesforthousandsofyears.Theyhavedesignedmanytypesofbridges.Eachbridgeissuitedtoitsspecial__16__.Theengineercanchoosethetypebestsuitedtotheriverandthe__17__nearby.

　　Whatchoicedoeshehave，andwhyisone__18__thantheothers？Onewayforyoutofindoutistomakeafewbridgesoutofcardboard.Theywon'tbestrongenoughto__19__afive­tontruck，butyouwillfindoutsomeofthemain__20__ofbridgedesignbydoingsomeexperiments.

　　1．A．clothes B．socks C．legs D．feet

　　2．A．road B．route C．way D．course

　　3．A．all B．both C．none D．neither

　　4．A．long B．easy C．money D．strength

　　5．A．haveit B．findit C．tryit D．seeit

　　6．A．want B．workhard C．careforit D．weigh

　　7．A．promote B．permit C．plan D．profit

　　8．A．will B．won't C．can D．cannot

　　9．A．cars B．trucks C．animals D．people

　　10．A．wider B．deeper C．moreshallow D．morepopular

　　11．A．do B．make C．pass D．arise

　　12．A．breakout B．bringup C．bend