The teacher will set whether downloading is allowed before releasing the courseware, so some courseware can be downloaded and some courseware can't be downloaded. The downloadable courseware will be displayed on the right when viewed on the computer. Just click "Download". You can preview it on your mobile phone, but you can't download it at present. If you click the download button to download ppt online, it is generally no problem. You can use ppt software to open it on your computer. If it is a ppt file in Baidu library, click the download button to download it correctly (the library does not support downloading tools such as Thunder to download documents).