Why might we protect an area against erosion?

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

Concealer circle oh in which arc xy measures 16 pi centimeters the length of the radius of the circle is 32 cm what is the circumference of the circle

Russia is to the east if germany ? true or false