相信有时是痛苦的。但如果停止相信，什么都不会开始。
信じることは、時に苦しい。でも、信じることをやめたら、何も始まらない。
Sometimes the simplest melodies are the most powerful.
Every improvement in the circumstances of the society tends either directly or indirectly to raise the real rent of land, to increase the real wealth of the landlord, his power of purchasing the labour, or the produce of the labour of other people.
给定系统中的酸和碱不是绝对的，而是相互关联的。