main,主要的，stay,支撑，维持。比喻用法。

1. Cocoa is the country's economic mainstay.

可可是这个国家的经济支柱。

2. Agriculture is still the mainstay of the country's economy.

农业仍然是这个国家经济的主要支柱.

3. After the father's death the son became the mainstay of the family.

父亲死后,儿子就成了这个家庭的主心骨.

4. They were the mainstay in the War of Resistance Against Japan.

他们是抗日战争的中流砥柱.

5. This principle of collective bargaining has been a mainstay in labor relations in this country.

这一集体谈判原则已经成为该国劳动关系的重要基础。