The virtual machine cannot be connected to the Internet, please move to: https://blog.csdn.net/qq_38786209/article/details/79997301
Open Ubuntu's settings, click Software and Updates, as shown in the figure:
Then click the Download from: drop-down option, as shown in the figure:
Select another site, as shown in the figure:
Click to select the best server, as shown in the figure:
It will automatically test, which mirror download speed is faster, as shown in the figure:
After the test is successful, click to select the server, and then it will ask for a password, let it reload, wait After completion, you can use the fastest mirror source to download:
