Itwasarainymorningtwoyearsago．ShirleyHuxhamwascyclinggentlydownhill．Asshewavedtoafriend，herbikesliduncontrollablyonthewetroad，throwinghertotheground．"I'dnevereventhoughtofbuyingahelmet，"shesays．Formonthsshewaspartlyparalysed（瘫痪的） downherleftsideandstillhashealthproblemstoday．
SomemightthinkthatShirleywasjustunlucky．Howdangerouscanitbetofallfromabicycle？Infact，eachyearonBritain'sroadsmorethan200peoplearekilledandatleast4，000seriouslyinjuredonbicycles．Butthesenumbersdon'ttellthewholestory：themajorityofthedeadandinjuredwerenotwearinghelmets．
AstudyofbicycleaccidentsintheUSfoundthathelmetscouldreducetheriskofseriousheadinjuryby85percent．YetitisestimatedthatinBritain，nomorethanfivepercentofbicycle-riderswearhelmets．Whydon'tmorecyclistswearthem？
Peoplethinkthathelmetslookfoolish，thatthey'reinconvenient，andthataccidentsonlyhappentootherpeople．
Oneofthewrongideasbicyclistshaveisthatlowerspeedscanputthematlessriskthanmotorcyclists，whoarelegallyobligedtowearhelmets．Infact，accordingtoaBritishreport，ahigherpercentageofbicycliststhanmotorcyclistssufferheadinjuries．Andtheirinjuriescanbejustassevere．
Helmets，however，canmakeabigdifference．Shirleywasn'tjustunlucky．Ifshehadwornahelmet，shewouldn'thavespentmonthsinhospital．Whytaketherisk？
38．ThereasonwhyShirleygotbadlyinjuredwasthat___．
A．Shewasridingherbicycledownhilltoofast．
B．Herfriend'swavingtohermadeherlosecontrol．
C．Sheignoredtheimportanceofwearingahelmet．
D．Thegroundwasbarelywet．
39．Whichofthefollowingstatementsisrightaccordingtothepassage___？
A．Wearinghelmetswillreducetheriskofbeingkilledby85%．
B．Nearly5percentofbicycle-riderswearnohelmetinUK．
C．Motorcyclistssuffermoreheadinjuriesthanbicyclists．
D．InUKamotorcyclist'swearingnohelmetisagainstthelaw．
40．Peopledon'tlikewearinghelmetsduetothefollowingreasonsexcept___．
A．Wearinghelmetsmakesthemlooksilly．
B．The
