sustain ·verb (SUPPORT)
Definition: to support someone or something so that they can live or exist Level: C2
他的兼职工作几乎无法维持他一个人的生活，更不用说养家了。
His part-time job could barely ___sustain him, let alone a family.
在昂贵的城市里，一份薪水可能不足以维持一个家庭。
A single salary might not be enough to ___sustain a household in an expensive city.
保护工作对于维持这一生态系统微妙的平衡至关重要。
Conservation efforts are crucial to ___sustain the delicate balance of this ecosystem.