这句话里包含了虚拟条件句,如果不倒装就是:Theacrobathadtoacknowledgehecouldverywelldieifheweretoperformit.

　　虚拟条件句的从句部分含有were,should,或had时,可省略if,再把were,should或had移到从句的句首,实行倒装.例如：

　　Weretheyherenow,theycouldhelpus.=Iftheywereherenow,theycouldhelpus.他们现在在的话,就会帮助我们了.

　　Hadyoucomeearlier,youwouldhavemethim.=Ifyouhadcomeearlier,youwouldhavemethim.你来得早一点,就碰到他了.

　　Shoulditrain,thecropswouldbesaved.=Wereittorain,thecropswouldbesaved.假如下雨,庄稼就有救了.

　　注意：在虚拟语气的从句中,动词'be'的过去时态一律用"were",不用was,即在从句中be用were代替.例如：

　　IfIwereyou,Iwouldgotolookforhim.如果我是你,就会去找他.

　　Ifhewerehere,everythingwouldbeallright.如果他在这儿,一切都会好的.