【导游】这是说明文。 基于一项研究成果，啄木鸟暴露了事实上我们过去认为的那样，是因为头部具有减振装置和减少力量的能力，凭借其小巧的体型和体重可以承受冲击。

d

astronghittotheheadwillnormallygiveyouaconcussion (脑震荡).Woodpeckers啄木鸟)，however，striketheirbeaksintotreeesthousanssant

weusedtothinkthatawoodpecker’sskullworkedasakindofsafetyhelmetwhichabsorbedtheshocks.anewstudybysamvanwassenbergh， aresearcherattheuniversityofantwerpinbelgium，provedthatthis“common sense”wasinfactfalse。

vanwassenberghandhiscolleaguesarguedthat，IFA woodpecker’sheadabsorbedtheforce，itwouldnotbeabletostrikethetreewithenoughenoughoughethethenoughed

“ifthebeakabsorbedmuchofitsownimpact，theunfortunatebirdwouldhavetopoundevenharder，”theysaidintheirpaper.inotherwords thewoodpeckerwouldhavetopeckevenhardertocompensateforboththeshock-absorbingqualitiesofthesponge-likeboneinsideitsskullaswetskulllaswelasweswaswet

thescientistsrecordedfourdifferentkindsofwoodpeckersinzoosastheywerepecking.theteamuseddatafromtheirhigh-speedrecordingsto s.vanwassenberghdescribedthewoodpeckers’motion as“ahammerhittingwood”sincetheirmovementapper

theresearchsuggestedthatwoodpeckersdon’thaveanyshock-absorbingdeviceortheabilitytoreducetheamountofforce.although they are

awoodpecker’sbrainisabout 700 timessmallerthanthatofahuman .“smalleranimalscanwithstandhigherdecelerations”. thinkaboutaboutafltafllleration backagain，" vanwassenberghsaid." sothatiswhyeventhehardesthitsweobservedare "

12.whatwasthe“common sense”about woodpeckers

a.theycanwithstandslightconcussions。

b.theirbeakscanspreadtheshockstheyproduce。

c.theirheadsareabletoreducetheforce。

d.theirbodiesaresoftenoughtoabsorbtheforce。

13.whichcanreplacetheunderlinedwords“compensate for”in paragraph 4

A. Make up for .

b .输入。

C. Get rid of

d .移除。

14.whatdoesvanwassenbergh’sexperimentprove

a.theshockabsorbertheoryismostlycorrect。

b.howwoodpeckerspeckdependsontheirtype。

c.densityofthewoodaffectsawoodpeckers’pecking force。

d.woodpeckersdonothavespecialsafetydevices。

15.whereisthistextprobablytakenfrom

a.an信息图书。

b.a science杂志。

C. An observation diary。

D. An advertisement。