Ubuntu Lucid, cannot install ROS electric

edit

the error message is like this:

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:
  ros-electric-desktop-full: Depends: ros-electric-ros-tutorials (= 0.2.6-s1313715256~lucid) but it is not going to be installed
                             Depends: ros-electric-nodelet-core (= 1.6.0-s1313699788~lucid) but it is not going to be installed
                             Depends: ros-electric-geometry-tutorials (= 0.1.3-s1313715382~lucid) but it is not going to be installed
                             Depends: ros-electric-filters (= 1.6.0-s1313699862~lucid) but it is not going to be installed
                             Depends: ros-electric-slam-gmapping (= 1.2.3-s1317342644~lucid) but it is not going to be installed
                             Depends: ros-electric-stage (= 1.4.0-s1313712377~lucid) but it is not going to be installed
                             Depends: ros-electric-documentation (= 1.4.2-s1314918935~lucid) but it is not going to be installed
                             Depends: ros-electric-visualization (= 1.6.4-s1316797656~lucid) but it is not going to be installed
                             Depends: ros-electric-vision-opencv (= 1.6.1-s1313700748~lucid) but it is not going to be installed
                             Depends: ros-electric-perception-pcl (= 1.0.1-s1315517480~lucid) but it is not going to be installed
                             Depends: ros-electric-geometry-experimental (= 0.2.2-s1313712024~lucid) but it is not going to be installed
                             Depends: ros-electric-robot-model-visualization (= 0.1.2-s1313720142~lucid) but it is not going to be installed
                             Depends: ros-electric-rx (= 1.6.1-s1314995568~lucid) but it is not going to be installed
                             Depends: ros-electric-image-pipeline (= 1.6.1-s1314697348~lucid) but it is not going to be installed
                             Depends: ros-electric-simulator-gazebo (= 1.4.5-s1316581134~lucid) but it is not going to be installed
                             Depends: ros-electric-diagnostics-monitors (= 1.4.0-s1315002762~lucid) but it is not going to be installed
                             Depends: ros-electric-simulator-stage (= 1.4.0-s1313712506~lucid) but it is not going to be installed
                             Depends: ros-electric-geometry-visualization (= 0.1.1-s1315018274~lucid) but it is not going to be installed
                             Depends: ros-electric-image-common (= 1.6.0-s1313700642~lucid) but it is not going to be installed
                             Depends: ros-electric-bond-core (= 1.6.0-s1313699727~lucid) but it is not going to be installed
                             Depends: ros-electric-common-tutorials (= 0.1.2-s1313726273~lucid) but it is not going to be installed
                             Depends: ros-electric-ros-comm (= 1.6.2-s1313697791~lucid) but it is not going to be installed
                             Depends: ros-electric-visualization-common (= 1.6.2-s1316578083~lucid) but it is not going to be installed
                             Depends: ros-electric-driver-common (= 1.2.3-s1313700560~lucid) but it is not going to be installed
                             Depends: ros-electric-executive-smach (= 1.0.2-s1313706613~lucid) but it is not going to be installed
                             Depends: ros-electric-common-msgs (= 1.6.0-s1313699542~lucid) but it is not going to be installed
                             Depends: ros-electric-image-transport-plugins (= 1.4.1-s1313700830~lucid) but it is not going to be installed
                             Depends: ros-electric-xacro (= 1.6.0-s1313699925~lucid) but it is not going to be installed
                             Depends: ros-electric-robot-model (= 1.6.1-s1315358505~lucid) but it is not going to be installed
                             Depends: ros-electric-bullet (= 2.76.3-s1313700087~lucid) but it is not going to be installed
                             Depends: ros-electric-visualization-tutorials (= 0.2.3-s1316934842~lucid) but it is not going to be installed
                             Depends ...