首先下载Office 2019 for Mac安装文件，安装文件下载有两种方式
1.访问 https://go.microsoft.com/fwlink/?linkid=525133 获取最新的Office 2019 for Mac 安装程序包
2.访问 http://net.usst.edu.cn/2009/1111/c7352a150585/page.htm 下载学校提供的安装文件（可能不是最新版）
First download the Office 2019 for Mac installation file. There are two ways to download the installation file.
1. Go to https://go.microsoft.com/fwlink/?linkid=525133 to get the latest Office 2019 for Mac installer package
2. Visit http://net.usst.edu.cn/2009/1111/c7352a150585/page.htm to download the installation files copy from USST campus server. (may not be the latest version)
下载完毕后，在MacOS上安装Office 2019 for Mac软件，安装完毕后，请暂时不要启动Office，先请点击以下链接下载授权激活文件：
After the download is complete, install Office 2019 on your MacOS. After the installation is complete, please do not start Office.
First, please click the following link (recommended to save as a right click) to download the License Serializer file:
ftp://msftp.usst.edu.cn/Office 2019/Microsoft_Office_2019_VL_Serializer.pkg （建议右键另存为）
授权激活文件下载并成功安装后，即可正常完成Office 2019 的授权激活。
After the License Serializer file is downloaded and successfully installed, the authorized activation of Office 2019 has be completed.
如有更多疑问，请参考微软的官方文档：
For more questions, please refer to the official Microsoft documentation:
https://docs.microsoft.com/en-us/deployoffice/mac/volume-license-serializer
