"A book is a dream that you hold in your hand."

解释：处在有利的地位上想到道义，处在困难之中想到保持纯正。

The most profound truths are often the ones we avoid.

We must balance immediate energy needs with long-term sustainability goals.

Every book is a journey, and every journey is a book.

生命中最美好的东西都是免费的。显然，我们最宝贵的资源是时间。

The art of doing mathematics consists in finding that special case which contains all the germs of generality.

The best way to be happy is to be kind.