Since when has he been there?怎么翻译

Since when has he been there?怎么翻译 since when ,since then的区别（在线等）he came back from abroad in 1998,since when,he has been doing his business.这一句中为什么用since when 却不能用since then , 高二英语单词拼写:Since he has received a doctor'degree,he must be l__. 改错He has been to Shanghai since last week.He will be back tomorrow. Tom has been watching TV ______ he came home 是“when?”还是“since?” 英语翻译you should be with a guy who knows what he has when he has you. He has been an architect()he graduated from the university.A.after B.since C.before D.when It ——15 years since he left here.Awas B has been C has D will be 改错 I don't think it advisable that he will be assigned to the job since he has no experience wbatI don't think it advisable that he will be assigned to the job since he has no experience wbatsoever. he has been in english since last Simon has lived there when he was five对吗可不可以是；Simon has lived there when he was five或者Simon has lived there since he was fivewhen可不可以用于现在完成时 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? Do you know when he came here?Let me think.He here since he graduated.A.had come B.has been C.had been I don't think it advisable that Tom__th the job since he has no experience.A.is assignedB.will be assignedC.be assignedD.has been assignedwhy choose Bruce has lived in the village ()Gum Tree since he was bornA called B be called 选哪个为什么 Tom has been collecting stamps since接：he ten years old（be）用括号的动词填空 几道英语的练习题.How long【】you【】in the English club?【join,be】When 【】you 【】 the English club?【join,be】It【】/【】【】5years since he come to Beijing.【be】It【1】/【2】【】5years since he come to Beijing I don't know ______ it was that he moved to another city,but life has not been the same since he left.A when Bwhat Chow Dwhere