为什么屏幕看着模糊/花屏了？
The display resolution that is configured may not be the correct one for your screen. To solve this:
Go to the Desktop and start typing Settings.
Click on Settings.
Click Displays in the sidebar to open the panel.
Try some of the Resolution options and select the one that makes the screen look better.
连接多个显示设备
If you have two displays connected to the computer (for example, a normal monitor and a projector), the displays might have different optimal, or native, resolutions.
Using Mirror mode, you can display the same thing on two screens. Both screens use the same resolution, which may not match the native resolution of either screen, so the sharpness of the image may suffer on both screens.
Using Join Displays mode, the resolution of each screen can be set independently, so they can both be set to their native resolution.