Super-stormSandyslammedintotheeasternUnitedStatessixyearsago.Thewind-drivenwatercausedalotofflooding,especiallyintheregion‘ssubwaysystem.Nowtwoteenshaveinventedadevicethatcouldhelppreventfuturesubwayfloods.
InNewYorkCityalone,super-stormSandycausedanestimated$19billionindamage.Muchofthefloodwaterenteredthesubwaysystemthroughitsventilationgrates(通风栅).Thosemetalgrillsusuallylieatgroundlevel.Whenthesystemisshutdownaheadofaflood,engineerstrytocoverthosegrateswithplywood(胶合板)andsandbags.Butthefloodingoftenwashesawaythosemeasures,whichallowswatertoflowintothetunnels.Raisingthosegratesevenatinybitabovegroundlevelwouldcostalotofmoney.Otherideashaveincludedbuildingtallchimneysaroundtheholes.Thatwouldraisethegratesandcostalotofmoney,too.
KyleandRaymondcameupwithadifferent,lessexpensiveidea.Theydesignedametalgratewithabuilt-in,adjustablecover.Whentrainsarerunning,onepartofthegrateslidesopentobringinfreshair.Butwhenthesystemisshutdown,thatpartcanbeslidshuttocompletelyblockthegrate.
Theirgrateisthesamesizeasthegratesusednow.So,itwouldbesimple,theysay,toliftouttheoldgrateanddropinareplacement.Theirdesignincludestamper-prooffeatures,whichcanpreventfromoperationmistakes.Theymakesurethatpeopledon‘tintentionallyshutoffairflowduringnormalconditions.Forpeoplewiththeproperkey,itwouldonlytakeaminuteortwotoclosethegrateaheadofaflood.
1.What‘sthesecondparagraphmainlyabout?
A.Thestepstooperategrates.
B.Themeasurestopreventflood.
C.Thefunctionofplywoodandsandbags.
D.Thedisadvantageofpresentsubwaysystem.
2.Whichofthefollowingwordsbestdescribesthetwoteens‘newinvention?
A.Costly. B.Time-saving.
C.Practical. D.Conventional.
3.What‘sthepurposeofdesigningthetamper-prooffeature?
A.Toreplacetheoldgratecorrectly.
B.Toclosethegrateaheadofaflood.
C.Toensureairflowinnormalconditions.
D.Tostopthetrainspeedingupunexpectedly.
4.Wheredoesthetextmostprobablycomefrom?
A.Anewsreport.
B.Anadventurousstory.
C.Anintroductiontonewequipment.
D.Aguidebookofmakinggrates.
