Carat reefs 2 biotic factors

Where the main factor that enabled the growth of cities and civilizations was the existence of

The magnitude of an earthquake is typically calculated according to the scale.           a. mercalli   b. fujita   c. richter   d. saffir-simpson  

Explain the reason for having an equator and a prime meridian. how do these two lines us to navigate our world? describe your opinion in at least two to three sentences.