To labor hard to little avail
劳多工少
Benefit principle(of taxation)
(税收的)受益原则
Medicines are of no avail
不可救药
were of little avail
不怎么有效
benefit of insurance clause
保险利益条款
benefit all mankind
裨益全人类
avail oneself of loopholes
见缝就钻
benefit of the doubt
裁判员对可疑情况无把握时不对有关运动员作不利判定
avail oneself of the opportunity to
借此机会
avail oneself of the opportunity to…
可乘之机
Benefit more than the cost
超值效益