解释：局势安定的国家，常常是富足的；局势 动乱的国家，常常是贫穷的。

The world is a book, and those who do not travel read only one page.

The key to success is to keep going even when things seem impossible.

我得到的最好建议是保持谦逊和努力工作。

The computer is the first metamedium, and as such it has degrees of freedom for representation and expression never before encountered.

我不让恐惧控制我，我控制恐惧。

物体的加速度与所受的合外力成正比，与物体的质量成反比。加速度的方向与合力的方向相同。