Ubuntu 소프트웨어 센터: 문제를 해결할 수 없습니다. 패키지가 손상되었습니다.

Ubuntu 14.04 LTS에서 패키지 소프트웨어 센터를 찾을 수 없습니다.

터미널을 통해 설치를 시도했지만 다음 오류가 발생했습니다.

ravip@LP204:~$ sudo apt-get install software-center
[sudo] password for ravip: 
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:
 software-center : Depends: software-center-aptdaemon-plugins but it is not going to be installed
                   Depends: python-gi but it is not going to be installed
                   Depends: python-gi-cairo but it is not going to be installed
                   Depends: python-aptdaemon (>= 0.40) but it is not going to be installed
                   Depends: python-aptdaemon.gtk3widgets but it is not going to be installed
                   Depends: oneconf (>= 0.2.6) but it is not going to be installed
                   Recommends: software-properties-gtk but it is not going to be installed
                   Recommends: sessioninstaller but it is not going to be installed
E: Unable to correct problems, you have held broken packages.

모든 Depends패키지가 Recommends설치되어 있고 최신 상태입니다.

어떻게 해결할 수 있나요?