What happened to Apple 13 clip video running to the front?

In this case, the sound and the picture are separated. Processing method: first put the video on the video track, left-click it, then find "Split Audio" in the "Options" column of the upper right window, and click it to split the audio. Then click on the audio on the audio track and hold down the mouse to adjust the audio to the left or right until it is synchronized with the video, and then start again.