What is alluvial soil in the ganges plain, and why do farmers like it?

Which of the following describes what rocks usually are composed of ,

Impressions of tropical swamp plants were observed on rocks in polar regions. the impressions were dark black imprints, which means the fossils are examples of ( 1 ) the fossils tell us that polar regions ( 2 ) ( 1 ) a. carbonization b. mineralization c. trace fossils ( 2 ) a. had tropical plants that can grow in ice b. might have had a diffierent climate in the past c. will have abundent vegitation

The map above shows where people live in the united states. areas that are darker blue are areas where people live close together. areas that are lighter colors are places where people live farther apart. as a geographer, if you were to study where people live and why they choose to live in these places, which of the six essential elements of geography would you be using?