Toaworker,________fromthepointofviewofsocietyisnecessarylaborisfromhisownpointofviewvoluntaryplay.
A
本题要求填入一个关系代词引导主语从句，并在主语从句中作主语，所以选 what。
—Youwerebraveenoughtoraiseobjectionsatthemeeting.
—Well,nowIregret________that.
Thetrafficwasheldupformorethanthirtyminutes,________causedmetoarrivelate.