我尝试在 16.04 LTS 上安装 R，但出现以下错误。我尝试了各种论坛上提供的所有可能的解决方案，但都没有成功。请提出建议。
sak@bav:~$ sudo apt-get install r-base
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:
r-base : Depends: r-base-core (>= 3.5.1-1xenial) but it is not going to be installed
Depends: r-recommended (= 3.5.1-1xenial) but it is not going to be installed
Recommends: r-base-html but it is not going to be installed
E: Unable to correct problems, you have held broken packages.