When he suddenly ________ up the subject of genetic engineering, there was an embarrassedsilence.
A、tookB
暂无解析
Itisusefultoscience_______theearthasanobjectinspace.
_______themovieIwouldhavefinishedmypaperlastSunday.
Humanbehaviorismostlyaproductoflearning________thebehaviorofanimalsdependsmainlyoninstinct.
Aftersomanydayswithoutrain,thegroundquickly________thelittlerainthatfelllastnight.
I'msorryIforgottowrite;Ihadsomuchelse________mymind.
