As I said in your other post/question on the same topic, you have to rephrase your question in order for us to help you. =)
Wind erosion is the main cause. And since it is the desert that wind can pick up tiny sand rock particles that slowly grind against the rock. Over time the erosion will give a jagged rock the smooth features as if it had been submerged in a river for the roughly same period of time.
A. Help take care of those in need, such as the poor.
This is a tenet of social programs and socialism.
Debido a su gran tamaño y sus características geográficas, en algunas culturas, América se divide tradicionalmente en América del Norte, América Central, y América del Sur. Algunos geógrafos consideran a América Central como una subregión dentro de América del Norte
