解决一个数学问题就是揭开宇宙拼图的一块。
The dairy industry must evolve with consumer needs, or we risk becoming irrelevant.
I went to the woods because I wished to live deliberately. I wanted to live deep and suck out all the marrow of life, to put to rout all that was not life.
Understanding the real lives of the poor is the first step toward designing effective policies to help them.