Briefly describe the geographic coordinate system. what is the importance of greenwich, england?

Mexico city is an example of how humans alter their environment because it was a. one of the world’s largest cities b. built on drained and filled lake beds c. built after conquest by the spanish d. once the capital of the aztec empire

Which layer surrounds the center of the earth? a: crust b: core c: mantle

In russia which of these challenges affects the transportation of both petroleum products and other goods?