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

charity是爱心、怜悯的的意思。但是如果改成by的话我都不知道什么意思。

live on是固定短语,以。。。为食,靠。。。生活。
这句话的意思是他们很穷,靠施舍生活。所以先A。

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.