What is their main source of income?

他们的主要收入来源是什么？

Research shows that young people still look to parents as their main source for health information.

研究表明年轻人仍然指望父母作为他们主要的健康信息来源。

Our use of fossil fuels is the main source of excess greenhouse gases.

我们对化石燃料的使用是温室气体过量的主要来源。

The main source of income, tourism, is expected to dry up completely this summer.

作为主要收入来源的旅游业预计将在今年夏天彻底枯竭。

Red meat was the main source of octopine, which was good for losing weight.

红肉是肉碱的主要食物来源，肉碱有利减肥。