2.Isn't a pleasure when your friends come to see you far away?有朋自遠方來,不亦樂乎?
3.Learn the new while reviewing the old.溫故而知新。
4.What you know, you know .What you don't know you don't know.知之為知之,不知為不知。
5。Do not to do others when you would not like .己所不欲勿施於人。