Complex social
systems developed
into early civilizations

The difference(s) between the grand canyon and valles marineris is/are: (a) the grand canyon was formed by water, but valles marineris was not. (a) valles marineris is much longer than the grand canyon. (c) valles marineris is much wider than the grand canyon. (d) valles marineris has large volcanoes near it. all of the above

Witch layer of the atmosphere has the most air pressure

Crisis in rivalries between the serbs, croatians and muslims has been going on for centuries and only intensified during the 1990s when non-communist rulers were elected