更新时间：2018-06-04 16:30作者：王华老师
C.OnMarch15thD.OnApril21st.
23.Whattypeofwritingisthistext?
A.Anexhibitionguide.B.Anartshowreview.
C.Anannouncement.D.Anofficialreport.
B
Passengerpigeons(旅鸽)onceflewovermuchoftheUnitedStatesinunbelievablenumbers.
Writtenaccountsfromthe18thand19thcenturiesdescribedflocks(群)solargethattheytheskyfor
hours.
Itwascalculatedthatwhenitpopulationzxxkreacheditshighestpoint,theyweremorethan3billlion
passengerpigeons—anumberequalto24to40percentofthetotalbirdpopulationintheUnitedStates,makingitperhapsthemostabundantbir