答え1
ゲスト追加 インストール後に画面解像度が高くなるからです。解像度を下げてみてください。設定を変更する手順は次のとおりです。
~からhttps://help.ubuntu.com/stable/ubuntu-help/look-solution.html.en
Open the Activities overview and start typing Settings.
Click on Settings.
Click Devices in the sidebar.
Click Displays in the sidebar to open the panel.
If you have multiple displays and they are not mirrored, you can have different settings on each display. Select a display in the preview area.
Select the resolution or scale, and choose the orientation.
Click Apply. The new settings will be applied for 20 seconds before reverting back. That way, if you cannot see anything with the new settings, your old settings will be automatically restored. If you are happy with the new settings, click Keep Changes.