Haveyoueverwondered?

1.Whydoairplanestakelongertoflywestthaneast?

Itcantakefivehourstogowest-eastfromNewYork(NY)toLondonbutsevenhourstotraveleast-westfromLondontoNY.Thereasonforthedifferenceisanatmosphericphenomenonknowasthejet(喷射)stream.ThejetstreamisaveryhighaltitudewindwhichalwaysblowsfromthewesttotheeastacrosstheAtlantic.Theplanesmovementaconstamsairspeedthusgofasterinthewest-eastdirectionwhentheairmovingwiththewindthanintheoppositedirection.

2WhatwouldhappenifthegravityonEarthwassuddenlyturnedoff?

Supposingwecouldmagicallyturnoffgravity.Wouldbuildingsandotherstructuresfloataway?WhathappenedwoulddependonhowstronglythethingswereattachedtotheEarth.TheEarthismovingatquiteaspeedmovingatoverathousandmilesperhour.Ifyouturnsomethingroundyourheadonastringitgoesaroundinacircleuntilyouletgoofthestronggoofthestring.ThingsnotattackedtotheEarthwouldflyoffinastraightline.Peopleinbuildingswouldsuddenlyshoot upwardsatagreatspeeduntiltheyhittheceiling.Mostthingswouldflyoffintospace.

1.Whatinformationcoawegetfromthefirstpassage?

A.tistheietstoomnthataffeetshowfastairplanesfly.

B.Planesgoslowerwhentheyaremovingwiththewind.

C.IttakesmoretimetoflyfromNYtoLondonthanfromLondontoNY.

D.ThejetstreamalwaysblowsfromtheeasttothewestacrosstheAtantic.

2.Theword“shoot”underlinedinthe2ndpassageprobablymeans“__________”.

A.sendfor

B.movequickly

C.comeout

D.growquickly

3.Itcanbeinterredthatwithoutgravity_________.

A.buildingsandotherstructureswouldfloataway

B.treesandbuildingswouldnotsoeasilyflyoff

C.somethingaroundyourheadwouldnotfloataway

D.everythingoutsidebuildingswouldflyoffintospace

4.Wherecanwemostprobablyreadthistext?

A.Insresearchpaper

B.Inatortstory.

C.Inatravelmagazine.

D.Inastudent’sbook.