File-Import-Import the cartoon you want to cut, drag it to the workspace below, drag the red pointer to the position you want to cut, find the razor tool in the lower right corner, cut it at the place you want to cut, and then separate it. You can cut the animation into many segments by the same operation, click on the unwanted segment and delete it.
In addition, it should be noted that video and audio are integrated. If you don't want intermittent sound, click the speaker next to the audio to turn off the sound.
Similarly, import a complete sound and insert it.
So that the next video can play the full sound.
When finished, you can export it-movie or Adobe media encoder, select the type you want, save it, and then render it.