Some concepts about waves: Amplitude(振幅)：the maximum displacement that a particle can make in the medium. Peak and Valley(波峰与波谷)： Wavelength(波长)：the minimum distance between any identical point along the direction of wave propagation Period(周期)：the period of the particle in oscillationSome concepts about waves: Amplitude(振幅）: the maximum displacement that a particle can make in the medium. Peak and Valley(波峰与波谷）: Wavelength（波长）:the minimum distance between any identical point along the direction of wave propagation Period（周期）：the period of the particle in oscillation