阅读理解
Therehavebeenmanygreatinventionsorthingsthatchangedthewaywelive．Thefirstgreatinventionwastheonethatisstillveryimportanttoday——thewheel．Thismadeiteasiertocarryheavythingsandtotravellongdistance．
Forhundredsofyearsafterthattherewerefewinventionsthatasmucheffectasthewheel．Thenintheearly1800stheworldstartedtochange．Therewaslittleunknownlandleftintheworld．Peopledidn'thavetoexploremuchanymore．Theybegantoworkinsteadtomakelifebetter．
Inthesecondhalfofthe19thcenturymanygreatinventionsweremade．Amongthemwerethecamerathelightandtheradio．Theseallplayabigpartinourdailylifetoday．
Thefirstpartofthe20thcenturysawmoregreatinventions．Thehelicopterin1909movieswithsoundin1926thecomputerin1928jetplanesin1930．Thiswasalsoatimewhenanewmaterialwasfirstmade．Nyloncameoutin1935．Itchangedthekindofclothespeoplewore．
Themiddlepartofthe20thcenturybroughtnewwaystohelppeoplegetoverdiseases．Theyworkedverywell．Theymadepeoplehealthierandallowedthemtolivelonger．Bythe1960smostpeoplecouldexpecttolivetobeatleast60．
Bythistimemostpeopleindevelopedcountrieshadaverygoodlife．Ofcoursenewinventionscontinuedtobemade．Butmannowhadadesire(渴望)toexploreagain．Theearthwasknowntomanbutthestarswerenot．Manbeganlookingforwaystogointospace．Russiamadethefirststep．ThenUnitedStatestookastep．SincethenothercountriesincludingChinaandJapanhavemadetheirownstepsintospace．
In1969mantookhisbiggeststepawayfromearth．Americansfirstwalkedonthemoon．Thisiscertainlyjustabeginningthough．Newinventionswillsomedayallowustodothingswehaveneveryetdreamedof．
(1)
A．
whycarswereveryimportant
B．