16. Courtesy costs nothing. 礼多人不怪。

　　17. Clumsy birds have to start flying early. 笨鸟先飞。

　　18. Custom makes all things easy. 习惯成自然。

　　19. Desire has no rest. 人的欲望无止境。

　　20. Difficult the first time, easy the second. 一回生，二回熟。