If the current trends hold, which of the following countries will probably surpass China as the most populous country in the world by 2050?

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

The two types of plains are coastal plains and lowland plains

Find the coordinates of a if b(-9,-10) is the midpoint of ac and c has the coordinates of (-1,9)