How are meteorological instruments useful for human beings?​

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

What border separates sonora and chihuahua national border state border physical boundary natural boundary

What is unusual about the iraq mountains ,in spite of their old age?