高二英语question!
In1988,hisbest-sellerABriefHistoryofTimewaspublished,【】whichheputforwardtheidea23timeitselfhasabeginning,andthatitwillhaveanend.Inconclusion,hehasmadeoutstandingcontributionstothefieldsofcosmologyandquantumgravity.
为什么是填in?我填了to我觉得是因为putforwardto