Add punctuation: We recommend that you upgrade your libgtk2perl packages
A: We recommend that you upgrade your libgtk2-perl packages.

Add punctuation: The theory has been that selenium especially selenomethionine affects protein called P53 and thereby causes the cancer to not be so aggressive
A: The theory has been that selenium, especially selenomethionine, affects protein called P53 and thereby causes the cancer to not be so aggressive.

Add punctuation: Originally a stand for a typewriter
A:
Originally a stand for a typewriter.