It is not by the grey of the hair that one knows the age of the heart. 白发并不能告诉你一个人心灵的年纪。——Edward B.Lytton If you do not plant knowledge when young, it will give us no shade when we are old. 如果年轻时不培养知识，年老时将没有乘凉的树荫。——Chesterfield Progress is the activity of today and the assurance of tomorrow. 进步乃今日之努力，明日之保证。——Emerso...
