2025年人教版九年级上册英语Unit 8阅读拔尖练.pptxVIP

Unit8

阅读拔尖练;温馨提示：点击进入讲评;温馨提示：点击进入讲评;外刊阅读—学会地道英语

重而圆的石块在水面上弹跳得更高

Haveyoueverspentagessearchingthebeachforflat(扁平的)stonestoskim(掠过)acrossthe

water?Well,youmighthavebeenwastingyourtimebecauseanewstudyhasfoundthatheavyandroundedstoneswillmakebiggerleapsoutofthewater.

Whenyouthrowathin,flatstoneacrossthewater,youwilloftenseeitskimalongthesurfaceseveraltimes.Witha;roundedstone,theeffectisdifferentbutnolesssatisfying.Itmightonlyskiponce,but,ifthrownright,itwillbounce(弹跳)muchhigher,accordingtoresearchers.

DoctorRyanPalmerandProfessorFrankSmithusedmathtoworkouthowtheshapeandweightofanobjectaffecthowithitsthewater.Theydiscoveredthatalthoughsomeheavystoneswillsink,stonesthathaveaspecialkindofcurve(曲面)willbounce.Thisisbecausethecurvechangeshowthestoneinteracts(相互作用)withthewater.Astone;thatisroundandheavypressesintothewatermoredeeplyandforlonger.Thispressureiswhatcausesthewatertomakethestoneupwards,__▲__.

Palmersaysroundrocksareagamechanger.“Ifyougetaheavierrock,youcangetasuper-elastic(超弹性的)response,whereyougetasinglebigbounceratherthanlotsoflittlebounces.It’sverysatisfyingifyoucanachieveit,”hesays.

PalmerandSmith’sresearchisallabouthowobjectsinteractwithsurfaces,soitwon’tjustbeusedtohelppeople;skimstones.Themainaimoftheresearchistostudyhowicebuildsuponaplanewhenitisflying,andhowitcanbecontrolledsothatitdoesn’tcauseengineproblems.Palmerexplainsthatit’sabouthowcrystals(晶体)oficeinteractwiththeshapeofanaircraftasitspeedsthroughtheair.Theresearchcouldalsobeusedtohelpplaneslandbetteronwater.

However,thatdoesn’tmeanthesciencecan’tbeusedtohavefun.Palmerencouragesstoneskimmerstotrysomestrangestonesandseewhathappens.;一、好词句深练

（一）根据语境用所给单词的