ubuntu安装g++失败

指令：apt-get install g++：结果如下：
错误 http://security.ubuntu.com/ubuntu/ maverick-security/main libgssrpc4 i386 1.8.1+dfsg-5ubuntu0.1
404 Not Found [IP: 91.189.91.15 80]
错误 http://security.ubuntu.com/ubuntu/ maverick-security/main libkrb5-dbg i386 1.8.1+dfsg-5ubuntu0.1
404 Not Found [IP: 91.189.91.15 80]
错误 http://security.ubuntu.com/ubuntu/ maverick-security/main libssl0.9.8-dbg i386 0.9.8o-1ubuntu4.1
404 Not Found [IP: 91.189.91.15 80]
无法下载 http://security.ubuntu.com/ubuntu/pool/main/k/krb5/libgssrpc4_1.8.1+dfsg-5ubuntu0.1_i386.deb 404 Not Found [IP: 91.189.91.15 80]
无法下载 http://security.ubuntu.com/ubuntu/pool/main/k/krb5/libkrb5-dbg_1.8.1+dfsg-5ubuntu0.1_i386.deb 404 Not Found [IP: 91.189.91.15 80]
无法下载 http://security.ubuntu.com/ubuntu/pool/main/o/openssl/libssl0.9.8-dbg_0.9.8o-1ubuntu4.1_i386.deb 404 Not Found [IP: 91.189.91.15 80]
E: 有几个软件包无法下载，您可以运行 apt-get update 或者加上 --fix-missing 的选项再试试？
这么多404，是下载站点不存在在了么？
要安装g++要怎么办尼