To teach how to live without certainty and yet without being paralyzed by hesitation is perhaps the chief thing that philosophy， in our age， can do for those who study it.

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。

我不是一个容易被影响的人。

流放不仅仅是一个地理概念；它是一种心态。

你在20多岁所做的事情将塑造你的未来。