apt GPG error

W: GPG error: http://extras.ubuntu.com trusty Release: The following signatures couldn‘t be verified because the public key is not available: NO_PUBKEY 16126D3A3E5C1192

sudo apt-key adv --recv-keys --keyserver keyserver.ubuntu.com 40976EAF437D05B5
sudo apt-key adv --recv-keys --keyserver keyserver.ubuntu.com 3B4FE6ACC0B21F32

sudo apt-key adv --recv-keys --keyserver keyserver.ubuntu.com 16126D3A3E5C1192

原文：http://www.cnblogs.com/antflow/p/7290814.html