我用 Ubuntu 18.04 启动了我的笔记本电脑（在没有安装方法的情况下尝试 Ubuntu）。然后，我运行以下命令：
sudo add-apt-repository universe
sudo add-apt-repository multiverse
sudo add-apt-repository ppa:gezakovacs
sudo apt install unetbootin
我收到以下消息：
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:
unetbootin : Depends: gksu but it is not installable or
kdesudo but it is not installable
Recommends: extlinux but it is not going to be installed
Recommends: unetbootin-translations but it is not going to be installed
E: Unable to correct problems, you have held broken packages.
我用谷歌搜索了一下，发现在这种情况下，我们应该在https://packages.ubuntu.com中搜索包名，我做了，结果在这里，但我没有在Bionic那里看到名称。这是否意味着我无法Unetbootin在 Ubuntu 18.04 中安装？如果可以，请告诉我该怎么做？