since when have you been so nice这是个什么句子,具体分析下语法,谢谢为什么要倒装

Since when have you become active?翻译 When I need you,you have once again chosen to leave,since you have already when you have lived here?since then you have lived here?区别 ____ have you been travelling?Since I was a boy.A Since when B When应该选哪个?为什么? Since when have you been in this item's segment of business (year)?Since when have you been in this item's segment of business (year)? Where have you been _____ you left home?A.before B.as C.since D.when ( ) have you studied English.A.When B.What C.since D.about Since I have seen you -()have you lived in shanghai?-Since we ()work here.A.When;have found B.How long;found C.When;have found D.How long;have found you have been playing golf since you were 16 years old when did he begin to play golf ________ have you been ________ I saw you last time?A.Since,where B.When,where C.Where,since D.While,as --- How long have you been collecting coins?--- ________.A.Since 5 years ago B.Since 5 years C.C.In 5 years D.When I was 5 By whom is the book written?Since when have you lived here?知道的大虾帮忙分析一下句子成分.重点 by 与 since 为什么要提前到句首?Thlanks. when you have any Since when have you known each otherwhen后面不是不能跟现在完成时吗为什么此句中这么用 since when have you been so nice这是个什么句子,具体分析下语法,谢谢为什么要倒装 you have been in Neijiang very long?Yeah _____my parents came here.A for B when C since 为什么呢 -You have been in Neijiang very long?-Yeah.______my parents came here.A.For B.As C.When D.Since