专题四“顺藤摸瓜”——明辨类题目Ⅰ
体验高考(·课标Ⅰ卷)Passengerpigeons(旅鸽)onceflewovermuchoftheUnitedStatesinunbelievablenumbers
Writtenaccountsfromthe18thand19thcenturiesdescribedflocks(群)solargethattheydarkenedtheskyforhours
Itwascalculatedthatwhenitspopulationreacheditshighestpoint,thereweremorethan3billionpassengerpigeons-anumberequalto24to40percentofthetotalbirdpopulationintheUnitedStates,makingitperhapsthemostabundantbirdintheworld
Evenaslateas1870whentheirnumbershadalreadybecomesmaller,aflockbelievedtobe1milewideand320miles(about515kilometers)longwasseennearCincinnati
Sadly,theabundanceofpassengerpigeonsmayhavebeentheirundoing
Wherethebirdsweremostabundant,peoplebelievedtherewasaneverlastingsupplyandkilledthembythethousands
Commercialhuntersattractedthemtosmallclearingswithgrain,waiteduntilpigeonshadsettled