The best time to plant a tree was 20 years ago. The second best time is now.
酸和碱不是绝对的,而是相对的。
If one only wished to be happy, this could be easily accomplished; but we wish to be happier than other people, and this is always difficult, for we believe others to be happier than they are.
生存的唯一方法就是不断前进。