Everyone is busy how to exploit the resources of material nature. That is advancement of civilization. Advancement of civilization means how to exploit the material resources. But they do not know, the foolish people do not know that is not advancement: Revision history
Diff selection: Mark the radio buttons of the revisions to compare and hit enter or the button at the bottom.
Legend: (cur) = difference with latest revision, (prev) = difference with preceding revision, m = minor edit.