An nod is as good as a wink to a blind horse. 对牛弹琴。

An oak is not felled at one stroke. 万事不能一蹴而就。

An occasion lost cannot be redeemed. 时机失了无法挽回。

An old dog barks not in vain. 老犬不空吠。

An old dog bites sore. 老狗咬人痛得很。

An old dog cannot alter its way of barking. 老狗难改吠声。

An old dog will learn no new tricks. 老家夥学不出新名堂。

An old physician, and a young lawyer. 医生年老的好，律师年轻的俏。

An old poacher makes the best keeper. 老偷猎者是最好的看守人。

An open door may tempt a saint. 一扇开著的大门可诱惑一个圣徒。

An optimist sees an opportunity in every calamity; a pessimist sees a calamity in every opportunity. 乐观的人在灾难中看到希望;悲观的人在希望中看到灾难。

An ounce of prevention is worth a pound of cure. 预防胜于治疗。

An ox is taken by the horns, and the man by the tongue. 牛因有脚而被抓，人因有舌而遭殃。

Answer a fool according to his folly. 以其人之道，还治其人之身。

An upright judge has more regard to justice than to men. 正直的法官重法胜于重人。