What longitudinal line separates the western and eastern hemisphere?

Long ago, people who lived in coastal north africa most often interacted with

Suggest two reasons why irrigation is important for human development of the desert

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