光波，无论是以太波还是其他波，在所有情况下都是时间上的周期性过程。
Every hour, she thinks, someone forges the rings, someone carves the cradle, someone loses the war.
No medicine cures what happiness cannot.
真相很少是纯粹的，也从来不是简单的。
乳制品不仅仅是一个行业；它是数百万人生活方式的一部分。
As we delve deeper into the quantum world, we find that topology is not just a mathematical curiosity, but a fundamental aspect of nature.