Several weeks had gone by __ I realized the picture was missing.应该填since,before?why?

She had several weeks sewing.She had several weeks to sewing.哪个对简单说明理由 Several weeks had gone by I realized the painting was missing. several weeks had gone by_____i realiize the painting was missing.Aas Bbefore Csince Dwhen several weeks ago 换现在完成时,是several weeks before还是for several weeks Several weeks had gone by ___I realized the paining was missing .6.Several weeks had gone by _b_ I realized the painting was missing.a、as b、 before c、 since d、 that 为什么选b Several weeks had gone by_____the judge realized his abuse of power,这句话为什么不可以...Several weeks had gone by_____the judge realized his abuse of power,这句话为什么不可以填when只可以用before Several weeks had gone by __ I realized the picture was missing.应该填since,before?why? 英语句子理解 21世纪大学英语课文Mother would count out to her a bundle of laundry that had accumulated over several weeks. Several weeks had gone by ______ I realized the painting was missing.a、as b、 before c、 since d、 that这题选b,为什么连接词之前有个by? Several weeks had gone by____ i realized the painting was missing.A.as B.before c.since D.when为什么选B而不是D Several weeks had gone by ________ realized the painting was missing.A.as B.before C.since D .w此题是哪一年的高考题 状语从句 Several weeks had gone by _____ I realized the painting was missing.中间的空为什么用before 而不用when? 谁有这篇文章,谢谢了several weeks ago the newspaper filled with the story of students at Fujian university who had been poisonedto death by his roommate I had a test two weeks later.怎么翻译?He would come back in several months.此句话would要改will We can - (see) the flower in several weeks. She died for several weeks 哪里错了,求改错 I bought several books two weeks ago.（改为同义句）I --------- ---------- several books for two weeks. But my teacher had been with me several weeks before I understood that everything has a name.请问各位这句怎么翻译才好,为什么用 before,可以用after