突然我的设置、背景显示、外观设置和软件和更新丢失或无法打开。我甚至尝试过
sudo apt install gnome-control-center
，但出现了这个错误
Reading package lists... Done
Building dependency tree
Reading state information... Done
Some packages could not be installed. This may mean that you have
requested an impossible situation or if you are using the unstable
distribution that some required packages have not yet been created
or been moved out of Incoming.
The following information may help to resolve the situation:
The following packages have unmet dependencies:
gnome-control-center : Depends: gnome-control-center-data (< 1:3.35) but 1:3.36.4-0ubuntu1 is to be installed
Depends: language-selector-gnome (>= 0.179~) but it is not going to be installed
Recommends: gnome-online-accounts (>= 3.25.3) but it is not going to be installed
Recommends: ubuntu-system-service but it is not going to be installed
E: Unable to correct problems, you have held broken packages.
甚至尝试sudo apt-get install ubuntu-desktop
过得到这个
Reading package lists... Done
Building dependency tree
Reading state information... Done
Some packages could not be installed. This may mean that you have
requested an impossible situation or if you are using the unstable
distribution that some required packages have not yet been created
or been moved out of Incoming.
The following information may help to resolve the situation:
The following packages have unmet dependencies:
ubuntu-desktop : Depends: gnome-control-center but it is not going to be installed
Depends: language-selector-gnome but it is not going to be installed
Depends: software-properties-gtk but it is not going to be installed
Depends: ubuntu-desktop-minimal but it is not going to be installed
Depends: ubuntu-release-upgrader-gtk but it is not going to be installed
Depends: update-manager but it is not going to be installed
Recommends: gnome-software-plugin-snap but it is not going to be installed
Recommends: nautilus-share but it is not going to be installed
Recommends: plymouth-theme-ubuntu-logo but it is not going to be installed
Recommends: ubuntu-software but it is not going to be installed
E: Unable to correct problems, you have held broken packages.
请建议我下一步该怎么做，提前谢谢。