everything,something,anything,nothing,everybody这些不定代词作主语...答:nothing, this, 疑问部分主语用it。Everything is ready, isn't it?陈述部分主语是不定代词everybody, anyone, somebody, nobody, no one 等,疑问部分常用复数they,有时也用单数he。Everyone knows the answer, don't they? (does he?)Nobody knows about it, do they? (does he?)...