Since 1949,when the People’s Republic of China was founde,it is not the first time for China to develop its western part.从上句可知,中国是在什么时候进行第一次发展西方地区

since when The book was written in 1946,_______ the education system has witnessed great changes.A.when B.during which C.since then D.since when The Spring Festival is the time ________ children receive giftswhile as since when选哪个,谢谢 翻译Since when was this when和since的用法 since when ,how long 区别 1.It was some time___we realized the truthA.when B.until C.since D.before when the news came __the war broke out he decied to serve.since which that because Since when does the Joker have red hair?有什么寓意 the book was written in 1946,-----the education system has saw great changes.答案用since when 为什么不用since which 代since 1946 ?since 是介词定语从句中不是要介词加关系代词的吗 It was six years ago( )the teacher graduated from our college.A.that B.when C.when that D.since since then &since whenThe book was written in 1946,_______ the education system has witnessed great changes.A.since when B.since then 为什么选A不选B? the book was written in 1946,{since when }the education system has saw great changes.请说明一下括号中为什么用since when而不用since which,when为何能指代1946, 这是什么从句since when有无这种特殊用法在定语从句只19 when和since有什么区别?The man has been playing the guitar ___ he was a boy.为何这里只能填since? the book was written in 1946,-----the education system has saw great changes.问什么空不能说since which 而 只能是 since when.准确答案 谢谢 since illustrate什么意思这句话完整是 When this occurs, conflict resolution is extrodinarily difficult, as the Cold War and the recurrent ethnic conflicts since illustrate. The book was written in 1946,the education system has witnessed great charges.The book was written in 1946, the education system has witnessed great charges.A．when B．during whichC．since then D．since when ( )The book was written in1946,_____ the education system has witnessed great challenges.( )The book was written in1946,_____ the education system has witnessed great challenges. A.when B,during which C.since which D.since when 答