Why is it hard to farm in the yucatán peninsular?

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

If a population is growing quickly in a small area then what must increase as well

Why is immigration so important today?