Method:1
1.Go to System-> Administration-> Software Sources.(If it ask for password type your password and press OK)
2.Select other Software
3.Select Add and enter:
deb http://archive.canonical.com/ lucid partner
4.Open terminal.To open terminal go to Applications-> Accessories-> Terminal and type
sudo aptitude install acroread
Method:2
Download Adobe Reader directly from the Adobe website.
1.Visit
http://get.adobe.com/reader/otherversions/
2.Select Linux from the drop-down menu
3.Select your preferred language
4.Select the (.deb) pakage of latest version.
5.Click download now button.
6.simply save the file to disk.
7.Double-click the file for the installation to begin.
Commentluv test