当将 Cairo dock 添加到 Ubuntu 12.04 时，我收到此消息，提示我需要依赖项。我现在该怎么做才能继续安装？
The following packages have unmet dependencies:
cairo-dock-plug-ins : Depends: libetpan15 (>= 1.0) but it is not installable
E: Unable to correct problems, you have held broken packages.