What empire 500 years ago had no real concept of money? what was the unit of value in this empire?

60=2x+4y Solve for x and y

Ice storms occur when which of the following conditions prevail?

List three of the possible dangers from winter storms.

Considering how magma composition and temperature change as it rises toward the surface, categorize each of the magmas described below in terms of their position within the lithosphere and uppermost asthenosphere.

Which of the following Europe countries has marine west coast climate

Why is Dubai creating underwater resorts and reclaimed islands? Dubai has an incredible amount of money to spend on building projects. Dubai's population is growing at a very fast pace, some say too fast.

Where was the maya civilization located

The widespread presence of banana plantations in central america region has resulted in increased standard of living

Which of these has been the result of human activity? a) glaciers melt more b) volcanoes erupt more landslides happen more d) earthquakes happen more

Which types of stars have extremely intense gravitational and magnetic fields?