The program 'curl' is currently not installed

http://askubuntu.com/questions/259681/the-program-curl-is-currently-not-installed
Error Information:
The program ‘curl’ is currently not installed. You can install it by typing:
sudo apt-get install curl

Method:
% sudo sed -i -e ‘s/us.archive.ubuntu.com/archive.ubuntu.com/g’ /etc/apt/sources.list
%sudo apt-get update
%sudo apt-get install curl

Not Succeed.
may because the packages for old releases have been moved to old-releases.ubuntu.com when they reached their end of official support from Canonical.need