Literature is the most subversive weapon because it changes minds, not by force, but by persuasion.

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.

解释：每种药材的生长都有其特定的环境和条件，说明药材产地与品质的关系。