The top layer of the earth is called the crust, this is made up of tectonic plates which shift and move in direction, it is the collisions and abrasions caused by the friction forces eroding the edges of these plates which push us the crust, and pour out lava and other rock causing the mountain ranges to form, this process continually happens and over millions of years has changed the surface of the planet, created vast mountains and continents. The lower spaces are those which the oceans fill, and the higher regions above sea are the continents.
The NAFTA (North American Free Trade Agreement) is the agreement that has lowered trade barriers between Mexico and the rest of North America. It was signed January 1, 1994.
