请哪位高手根据英语短文回答两个问题.ThanksgivingDayisalwayscelebratedonthefourthThursdayofNovember.ItisthemosttraditionalofAmericanholidays.ThefirstthanksgivingwasheldinMassachusettsin1621.Afterayearofgrea

　　请哪位高手根据英语短文回答两个问题.

　　ThanksgivingDayisalwayscelebratedonthefourthThursdayofNovember.ItisthemosttraditionalofAmericanholidays.ThefirstthanksgivingwasheldinMassachusettsin1621.Afterayearofgreathardship,thePilgrimcolonistswantedtogivethankstoGodfortheirfirstharvest.TheyinvitedtheirIndianfriendstojointheminabigfeast.Todaytheholidayisstillcelebratedasadayforgivingthanks.Itisadayoffamilyreunionanditiscustomarytoinvitefriendstosharethemeal.Insomelargecities,therearecarnivalparadesforchildren.Inothercities,thereareimportantfootballgamesthatareplayedonThanksgivingDay.

　　thefirstthanksgivingdaywasheld

　　A,intheearly17thcentury

　　Bbeforthe17thcentury

　　thanksgicingdaywasoriginally_

　　A,adaytogicethankstogod

　　B,adayforfamilymemberstogettogether

　　我认为这两个都是选择A，可答案给的都是B，为什么？