The steps are as follows:

1. Open the main interface of DingTalk software and click the menu item of DingTalk class group.

2. Next, click the online class icon in the DingTalk class group chat window on the page that opens.

3. Then click the menu item of video conference teaching on the page that opens.

4. Then click the Start Meeting button on the page that opens.

5. Then click the "***Share Screen" button in the lower right corner of the opened page.

6. Click on the ***Share Screen option. Click "Turn on device audio" to enjoy screen sound.