学习是系统中产生的任何变化,这些变化或多或少会永久性地改变其适应环境的能力。
没有人民的普遍知识,自由就无法得到保障。
The white race believes—believes with all its heart—that it is their right to take the land.
The only limit to our realization of tomorrow is our doubts of today.
Without sacrifice, there is no freedom.