课业要求用libc++但是我的版本太旧，没法用。我是新手，完全不懂怎么回事啊！！我用的command line是 sudo apt-get install libc++,结果出现了一列东西（note, selecting ...和xxxis already the newest version,之类的），最后出现的是以下内容
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:
libcgi-application-plugin-ajaxupload-perl : Depends: libgd-gd2-perl (>= 1:2.45-2)
Recommends: libcgi-application-plugin-json-bundle-perl but it is not installable
libcloog-isl-dev : Conflicts: libcloog-ppl-dev but 0.16.1-5 is to be installed
libclutter-gst-2.0-doc : Conflicts: libclutter-gst-doc but 1.6.0-2build1 is to be installed
libcuda1-304 : Conflicts: libcuda-5.0-1
libcuda1-304-updates : Conflicts: libcuda-5.0-1
libcuda1-331 : Breaks: libcuda-5.0-1
Breaks: libcuda-5.5-1
libcuda1-331-updates : Breaks: libcuda-5.0-1
Breaks: libcuda-5.5-1
libcunit1-ncurses : Conflicts: libcunit1 but 2.1-2.dfsg-1 is to be installed
libcunit1-ncurses-dev : Conflicts: libcunit1-dev but 2.1-2.dfsg-1 is to be installed
libcurl4-gnutls-dev : Conflicts: libcurl4-nss-dev but 7.35.0-1ubuntu2.3 is to be installed
Conflicts: libcurl4-openssl-dev but 7.35.0-1ubuntu2.3 is to be installed
libcurl4-nss-dev : Conflicts: libcurl4-gnutls-dev but 7.35.0-1ubuntu2.3 is to be installed
Conflicts: libcurl4-openssl-dev but 7.35.0-1ubuntu2.3 is to be installed
libcurl4-openssl-dev : Conflicts: libcurl4-gnutls-dev but 7.35.0-1ubuntu2.3 is to be installed
Conflicts: libcurl4-nss-dev but 7.35.0-1ubuntu2.3 is to be installed
E: Unable to correct problems, you have held broken packages.
怎么解决啊？
我试过用sudo apt-get update,结果那里也出现问题了。问题应该出在这些地方了：
Get:4 http://us.archive.ubuntu.com trusty-security Release [62.0 kB]
Err http://archive.ubuntukylin.com:10006 trusty InRelease
Err http://archive.ubuntukylin.com:10006 trusty Release.gpg
Unable to connect to archive.ubuntukylin.com:10006:
还有
W: Failed to fetch http://archive.ubuntukylin.com:10006/ubuntukylin/dists/trusty/InRelease
W: Failed to fetch http://archive.ubuntukylin.com:10006/ubuntukylin/dists/trusty/Release.gpg Unable to connect to archive.ubuntukylin.com:10006:
W: Some index files failed to download. They have been ignored, or old ones used instead.
求救！！！请帮帮我
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:
libcgi-application-plugin-ajaxupload-perl : Depends: libgd-gd2-perl (>= 1:2.45-2)
Recommends: libcgi-application-plugin-json-bundle-perl but it is not installable
libcloog-isl-dev : Conflicts: libcloog-ppl-dev but 0.16.1-5 is to be installed
libclutter-gst-2.0-doc : Conflicts: libclutter-gst-doc but 1.6.0-2build1 is to be installed
libcuda1-304 : Conflicts: libcuda-5.0-1
libcuda1-304-updates : Conflicts: libcuda-5.0-1
libcuda1-331 : Breaks: libcuda-5.0-1
Breaks: libcuda-5.5-1
libcuda1-331-updates : Breaks: libcuda-5.0-1
Breaks: libcuda-5.5-1
libcunit1-ncurses : Conflicts: libcunit1 but 2.1-2.dfsg-1 is to be installed
libcunit1-ncurses-dev : Conflicts: libcunit1-dev but 2.1-2.dfsg-1 is to be installed
libcurl4-gnutls-dev : Conflicts: libcurl4-nss-dev but 7.35.0-1ubuntu2.3 is to be installed
Conflicts: libcurl4-openssl-dev but 7.35.0-1ubuntu2.3 is to be installed
libcurl4-nss-dev : Conflicts: libcurl4-gnutls-dev but 7.35.0-1ubuntu2.3 is to be installed
Conflicts: libcurl4-openssl-dev but 7.35.0-1ubuntu2.3 is to be installed
libcurl4-openssl-dev : Conflicts: libcurl4-gnutls-dev but 7.35.0-1ubuntu2.3 is to be installed
Conflicts: libcurl4-nss-dev but 7.35.0-1ubuntu2.3 is to be installed
E: Unable to correct problems, you have held broken packages.
怎么解决啊？
我试过用sudo apt-get update,结果那里也出现问题了。问题应该出在这些地方了：
Get:4 http://us.archive.ubuntu.com trusty-security Release [62.0 kB]
Err http://archive.ubuntukylin.com:10006 trusty InRelease
Err http://archive.ubuntukylin.com:10006 trusty Release.gpg
Unable to connect to archive.ubuntukylin.com:10006:
还有
W: Failed to fetch http://archive.ubuntukylin.com:10006/ubuntukylin/dists/trusty/InRelease
W: Failed to fetch http://archive.ubuntukylin.com:10006/ubuntukylin/dists/trusty/Release.gpg Unable to connect to archive.ubuntukylin.com:10006:
W: Some index files failed to download. They have been ignored, or old ones used instead.
求救！！！请帮帮我
