说明：  横波与纵波的叠加，通过设置不同频率，相位可以得到横波与纵波的叠加图像，有利于更好的理解波的叠加。
(S-wave and P-wave superposition, by setting different frequency, phase transverse wave can be superimposed with the P-wave images, is conducive to a better understanding of wave superposition.)