When it realized how different the world seemed when it rolled so quickly,it stopped.帮我分析一下这个句子,为什么用两个“when”?作用是什么.还有“seemed”

Only when I left home ,did i realized how important it was to stay at home?此中为什么不用HAD I REALIZED? When it realized how different the world seemed when it rolled so quickly,it stopped.帮我分析一下这个句子,为什么用两个“when”?作用是什么.还有“seemed” Only when _____ how important it was to master English. A.did i work i realized B.I worked did IB.I worked did I realize C.did I work did I realize D.I work I realized it was only then( )how much trouble I had caused to him.A.when I realizeB.did I realize C.that I realizeD.that did I realize Only when I left my parents for Italy how much I loved them.CA.I realized B.I had realized C.had I realized D.did I realize 英语改错如题when he realized how he couldn't manage it,he asked me for help .But then we had onlyan hour to get to hthe airport 有两处错误 HOW-------WHAT BUT-----AND 英语改错如题when he realized how he couldn't manage it,he asked me for help .But then we had onlyan hour to get to hthe airport 有两处错误 HOW-------WHAT 为什么不能改成THAT If I ___ how awful the job was going to be,I wouldn‘t have accepted it.A .realized B.had realized C.was realized D.did realize 关于when引导的从句When it realized how different the world seemed when it rolled so quickly,it stopped.句子中为什么要用两个when,分别是什么作用呢.为什么用seemed这个动词,又该怎么翻译,作用是什么. An increasing number of students have rAn increasing number of students have realized how great an alternative a credit card is when it comes to purchasing items or procuing services.关键是那个：an alternative 怎么理解 It came me in a rush when i realized i love you so much. 1.It was some time___we realized the truthA.when B.until C.since D.before When he got to school ,he found the classroom was _____.He realized it was Sunday. I thought that it mattered,was when and where I said,then I realized ,the on I stop laughing when I realized she was serious about it. I stopped laughing when i realized Jen --------（对...认真）it It was some time ______ we realized the truth.A.It was some time ______ we realized the truth.A.when B.until C.since D.before I regret that I wasted so much time when i was in middle school How I wish you ___this earlierA:realized B:would realize C:had realized D:have realized