1、It is never too old to learn. 活到老，学到老。

2、There is no royal road to learning. 学问无坦途。/书山有路勤为径,学海无涯苦作舟。

3、A man becomes learned by asking questions. 不耻下问才能有学问。

4、Absence makes the heart grow fonder. 小别胜新婚；距离产生美；久别情更深。

5、When the cat is away, the mice will play. 山中无老虎，猴子称大王。

6、No cross, no crown. 不经历风雨，怎么见彩虹。