Scientists believe that Earth's tectonic plates move due to: convection.
the magnetic pull of the poles.
bombardment by objects from outer space.
Earth's spinning around its axis.

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

Suggest two reasons why irrigation is important for human development of the desert (4 marks)

Select the natural regions. delta denver forest georgia north america plateau stream