What are the 3 megacities?​

What are the similarities and differences in the way geologists and biologists approximate the age of the earth? justify your response in two or more complete sentences.

These factors threaten north americas ecosystems

When geographers describe how two places are related to each other spatially, they are describing a. where the places are located in relation to one another b. what kinds of natural environments are around each place c. how each place is changing over time d. what kinds of cultures are in each place