量子力学的本质在于它提供了一个数学框架，用于描述原子和亚原子层面上物质的行为。

写作就像在大理石上雕刻：每个词都必须精确且不可复制。

言论不能改变行动而又崇尚它，那就是说空话。 

"The best way to make a child laugh is to treat them like an adult."

The great ideological battles between liberalism and communism, or between democracy and authoritarianism, have been replaced by a general consensus on the desirability of liberal democracy.