The urban homeless are often in desperate need of sustenance.

城市里无家可归的人极其需要食物来维持生命。

He gave money for the sustenance of a poor family.

给一穷人家维持生活。

The earth brings forth large crops every year for the sustenance of man and beast.

大地每年生产出大量的农作物,供人畜食用。