To every action there is always opposed an equal reaction； or， the mutual actions of two bodies upon each other are always equal， and directed to contrary parts.

美国农民是我们经济中唯一必须以零售价购买所需一切，以批发价出售所产一切，并支付双向运费的人。

我总是相信，如果你陷入困境，也许事情并不顺利，你会变得更强大。