报错内容：
$ sudo apt-get install lm-sensors sensors-applet
Reading package lists... Done
Building dependency tree
Reading state information... Done
lm-sensors is already the newest version (1:3.3.4-2ubuntu1).
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:sensors-applet : Depends: libpanel-applet-4-0 (>= 3.2.1) but it is not going to be installed
E: Unable to correct problems, you have held broken packages.
1，尝试修复：
$ sudo dpkg --configure -a
$ sudo apt-get update
$ sudo apt-get autoremove
$ sudo apt-get -f install
没有起到作用。
2，根据报错内容提示，手动安装指定的软件包（libpanel-applet-4-0）：
$ sudo apt install libpanel-applet-4-0
解决。