Ubuntu 更新源失败
各位大神新装的Ubuntu14.04,更新源出现
W: Failed to fetch http://mirrors.sohu.com/ubuntu/dists/trusty-security/main/source/Sources Hash Sum mismatch
W: Failed to fetch http://mirrors.sohu.com/ubuntu/dists/trusty-security/restricted/source/Sources Hash Sum mismatch
W: Failed to fetch http://mirrors.sohu.com/ubuntu/dists/trusty-security/universe/source/Sources Hash Sum mismatch
W: Failed to fetch http://mirrors.sohu.com/ubuntu/dists/trusty-security/multiverse/source/Sources Hash Sum mismatch
W: Failed to fetch http://mirrors.sohu.com/ubuntu/dists/trusty-security/main/binary-i386/Packages Hash Sum mismatch
W: Failed to fetch http://mirrors.sohu.com/ubuntu/dists/trusty-security/restricted/binary-i386/Packages Hash Sum mismatch
W: Failed to fetch http://mirrors.sohu.com/ubuntu/dists/trusty-security/universe/binary-i386/Packages Hash Sum mismatch
W: Failed to fetch http://mirrors.sohu.com/ubuntu/dists/trusty-security/multiverse/binary-i386/Packages Hash Sum mismatch
W: Failed to fetch http://mirrors.sohu.com/ubuntu/dists/trusty-security/main/i18n/Translation-en Hash Sum mismatch
W: Failed to fetch http://mirrors.sohu.com/ubuntu/dists/trusty-security/multiverse/i18n/Translation-en Hash Sum mismatch
W: Failed to fetch http://mirrors.sohu.com/ubuntu/dists/trusty-security/restricted/i18n/Translation-en Hash Sum mismatch
W: Failed to fetch http://mirrors.sohu.com/ubuntu/dists/trusty-security/universe/i18n/Translation-en Hash Sum mismatch
W: Failed to fetch http://mirrors.sohu.com/ubuntu/dists/trusty-updates/main/source/Sources Hash Sum mismatch
W: Failed to fetch http://mirrors.sohu.com/ubuntu/dists/trusty-updates/universe/source/Sources Hash Sum mismatch
W: Failed to fetch http://mirrors.sohu.com/ubuntu/dists/trusty-updates/main/binary-i386/Packages Hash Sum mismatch
W: Failed to fetch http://mirrors.sohu.com/ubuntu/dists/trusty-updates/universe/binary-i386/Packages Hash Sum mismatch
W: Failed to fetch http://mirrors.sohu.com/ubuntu/dists/trusty-updates/multiverse/i18n/Translation-en Hash Sum mismatch
W: Failed to fetch http://mirrors.sohu.com/ubuntu/dists/trusty-updates/universe/i18n/Translation-en Hash Sum mismatch
W: Failed to fetch http://mirrors.sohu.com/ubuntu/dists/trusty-proposed/main/source/Sources Hash Sum mismatch
W: Failed to fetch http://mirrors.sohu.com/ubuntu/dists/trusty-proposed/multiverse/source/Sources Hash Sum mismatch
W: Failed to fetch http://mirrors.sohu.com/ubuntu/dists/trusty-proposed/universe/binary-i386/Packages Hash Sum mismatch
W: Failed to fetch http://mirrors.sohu.com/ubuntu/dists/trusty-proposed/universe/i18n/Translation-en Hash Sum mismatch
W: Failed to fetch http://mirrors.sohu.com/ubuntu/dists/trusty-backports/main/i18n/Translation-en Hash Sum mismatch
W: Failed to fetch http://mirrors.sohu.com/ubuntu/dists/trusty-backports/restricted/i18n/Translation-en Hash Sum mismatch
E: Some index files failed to download. They have been ignored, or old ones used instead.
怎么办呢?改了好几个源都不对