There is no direct folder to copy, so copying to MP4 is a bit troublesome. The steps are as follows:

1, right click to open.

2. Open the book folder.

3. Open the book3 folder, and then you will see a series of folders, such as reading the text of Unit 1.

Just open unit 1 and read it, and you will understand (there are three audio segments), but if you want to play MP4, you'd better change the file name to a text name.