What they didn't tell you in physics -- in eighth-grade physics -- but they should have, and I wish they had, was that if you multiply the frequency times the wavelength of sound or light, you get a constant.
但是他们在八年级物理课上没有告诉你的是 （他们应该告诉你的，我希望他们告诉你） 当你将频率乘以声音或者 光的波长，你将得到一个常量。