For cities, mountains can be both a help and hindrance. Whilst mountains can be a barrier to trade and transport, they form a natural line of protection from invasion. Therefore, many ancient cities thrived when located near mountains, with the reduced risk of attack affording them time to grow and prosper
Answer:
Water Erosion
Explanation:
The "Blue Caves" in Greece are a series of sea caves, also known as a littoral caves. Littoral caves are shaped primarily by wave action in the form of water erosion.
The resource that helped make Ghana wealthy is (a.gold)
Troposphere is the layer closest to earth, which includes the air that we breathe. After this comes the Stratosphere which includes the ozone layer and then the Mesosphere. After this it's the thermosphere and then the exosphere.
The one I didn't mention is the methosphere - this is the correct answer!
