点击收听音频讲解：
Day 8
Whenever you face something difficult, just remember water cuts through rock, not because of its strength, but because of its persistence.
当你遇到困难的时候，你要记住水可以切碎岩石，并非因其力大无穷，而是因为坚持不懈。
Key words:
difficult adj. 困难的；a difficult person/be difficult about 挑剔；苛刻；难对付
cut v. 切；cut me dead
strength n. 力量；国力（national strength）; comprehensive
persistence n. 坚持；persist in doing
because of/because 前者 单词；后者 句子
