They were poor,and lived -----charity A on B off C by D both A and C

问题描述:

They were poor,and lived -----charity A on B off C by D both A and C
为什么不是c .

live on是固定短语,“以.为食,靠.生活.”后接一个名词,而live by 是靠某种活动或技能生活,后接动名词.