1.    Envy has no holidays.

嫉妒之人无宁日。

2.    Don’t claim to know what you don’t know.

不要不懂装懂。

3.    Courtesy on one side only lasts not long.

来而不往非礼也。

4.    Diamond cuts diamond.

强中自有强中手。

5.    Each bird loves to hear himself sing.

孤芳自赏。

6.    Every day is not Sunday.

好景不在。

7.    Custom is a second nature.

习惯是后天养成的。