Todaybicyclesareelegantlysimplemachinesthatarecommonaroundtheworld.Manypeopleridebicyclesforrecreationwhereasothersusethemasameansoftransportation.ThefirstbicyclewasinventedinGermanyin1818.Becauseitwas

　　Todaybicyclesareelegantlysimplemachinesthatarecommonaroundtheworld.Manypeopleridebicyclesforrecreationwhereasothersusethemasameansoftransportation.ThefirstbicyclewasinventedinGermanyin1818.Becauseitwasmadeofwooditwasn’tverystrongnordidithavepedals(脚踏板）.Ridersmoveditbypushingtheirfeetagainsttheground.

　　In1839KirkpatrickMacmillanaScottishblacksmithinventedamuchbetterbicycle.Macmillan’smachinehadiron-coveredwheelstokeepthemfromgettingworndown.Healsousedfoot-operatedleverssimilartopedalssohisbicyclecouldberiddenataquickpace.Itdidn’tlookmuchlikethemodembicyclethoughbecauseitsbackwheelwassubstantiallylargerthanitsfrontwheel.AlthoughMacmillan’sbicyclescouldberiddeneasilytheywereneverproducedinlargenumbers.

　　In1861FrenchmanPierreMichauxandhisbrotherErnestinventedabicyclewithanimprovedpedalmechanism.Theycalledtheirbicycleavelocipede，butmostpeoplecalledita“boneshaker”becauseoftheeffectofthewoodandironframe.Despitetheimpolitenicknamethevelocipedewasahit.AfterafewyearstheMichauxfamilywasmakinghundredsofthemachinesannuallymostlyforfun-seekingyoungpeople.

　　TenyearslaterJamesStarleyanEnglishinventormadeseveralinnovationsthatrevolutionizedbicycledesign.Hemadethefrontwheelmanytimeslargerthanthebackwheelputagearonthepedalstomakethebicyclemoreefficient，andlightenedthewheelsbyusingwirespokes.Althoughthisbicyclewasmuchlighterandlesstiringtorideitwasstillclumsyextremelytop-heavy，andriddenmostlyforentertainment.

　　Itwasn’tuntil1874thatthefirsttrulymodernbicycleappearedonthescene.InventedbyanotherEnglishmanH.J.Lawsonthesafetybicyclewouldlookfamiliartotoday’scyclists.Thesafetybicyclehadequal-sizedwheelswhichmadeiteasiertoride.Lawsonalsoattachedachaintothepedalstodrivethebackwheel.By1893，thesafetybicyclehadbeenfurtherimprovedwithair-filledrubbertiresadiamond-shapedframeandeasybraking.WiththeimprovementsprovidedbyLawson;bicyclesbecameextremelypopularandusefulfortransportation.Todaytheyarebuiltusedandenjoyedallovertheworld.

　　【小题1】Thispassagewasmostli