thirty years before,they had moved to their cosy house.这里为什么用before不用ago?

为什么是thirty years ago 而不是thirty years before? Thirty five years ago和Thirty five years before有什么区别?不解.. it was thirty years until they were able to reunite 能代替 it was thirty years before they were吗 thirty years before,they had moved to their cosy house.这里为什么用before不用ago? Dr martin luther king 's murder took piace about thirty years ago,before many Americans were born Thirty years had passed----- he kenw it A.after B.when C.before D.while 为什么不选B呢 CODA THIRTY YEARS AFTER怎么样 uncle is thirty years old. since和before的区别!It is thirty years since we last met.这句话用before怎么说?since和before的区别到底是什么?这种It is句型什么是用since?什么时候用before? how he became prime minister had been prophesied thirty years before.请问这句话怎么翻译?HOW 在里面表示什么意思?谢谢! Does she aiways come before six thirty? 英语翻译he must be--------- ------------thirty years old thirty years later 用什么时态 another thirty years=同义短语 Thirty years or so ago什么意思? My uncle is thirty years old. My uncle is thirty years old. How was Shenzhen thirty years ago?意思