我正在运行 Ubuntu 14.04.3 LTS 并尝试安装 php5-gd php_extension，但出现以下错误：
以下软件包具有未满足的依赖项：php5-gd：依赖：php5-common（= 5.5.9+dfsg-1ubuntu4.11）但需要安装 5.5.14+dfsg-2+deb.sury.org~precise+1
我确信这是混合存储库的问题，但我无法确定问题所在。如能得到任何帮助，我将不胜感激。
编辑：这是我当前的来源：
deb us.archive.ubuntu.com/ubuntu/ trusty main restricted
deb-src us.archive.ubuntu.com/ubuntu/ trusty main restricted
deb us.archive.ubuntu.com/ubuntu/ trusty-updates main restricted
deb-src us.archive.ubuntu.com/ubuntu/ trusty-updates main restricted
deb us.archive.ubuntu.com/ubuntu/ trusty universe
deb-src us.archive.ubuntu.com/ubuntu/ trusty universe
deb us.archive.ubuntu.com/ubuntu/ trusty-updates universe
deb-src us.archive.ubuntu.com/ubuntu/ trusty-updates universe
deb us.archive.ubuntu.com/ubuntu/ trusty multiverse
deb-src us.archive.ubuntu.com/ubuntu/ trusty multiverse
deb us.archive.ubuntu.com/ubuntu/ trusty-updates multiverse
deb-src us.archive.ubuntu.com/ubuntu/ trusty-updates multiverse
deb us.archive.ubuntu.com/ubuntu/ trusty-backports main restricted universe multiverse
deb-src us.archive.ubuntu.com/ubuntu/ trusty-backports main restricted universe multiverse
deb security.ubuntu.com/ubuntu trusty-security main restricted
deb-src security.ubuntu.com/ubuntu trusty-security main restricted
deb security.ubuntu.com/ubuntu trusty-security universe
deb-src security.ubuntu.com/ubuntu trusty-security universe
deb security.ubuntu.com/ubuntu trusty-security multiverse
deb-src security.ubuntu.com/ubuntu trusty-security multiverse