HesaidthathehadlearnedsomeEnglishbefore.
Bythetimehewastwelve,Edisonhadbegantomakealivingbyhimself.
Tomwasdisappointedthatmostoftheguestshadleftwhenhearrivedattheparty.
Thestudents___busilywhenMissBrownwenttogetabookshe___intheoffice.
A.hadwritten,leftB,werewriting,hasleftC.hadwritten,hadleftD.werewriting,hadleft
答案D."把书忘在办公室"发生在"去取书"这一过去的动作之前,因此"忘了书"这一动作发生在过去的过去,用过去完成时。句中when表示的是时间的一点,表示在"同学们正忙于……"这一背景下,when所引导的动作发生。因此
hadnosooner…than刚……就……
Hehadnosoonerboughtthecarthanhesoldit.