When might it be important to know a currency's exchange rate

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

How have ethnic groups shaped the population in central america and the caribbean? how has migration shaped the population in central america and the caribbean? how has small land areas shaped population in central america and the caribbean? how has a rapid population growth shaped the population in central america and the caribbean?

Who developed the theory of plate tectonics?