What color can a human eye cant see

How does population distribution reflect a particular region’s economy?

Gold is not now being extracted from seawater. why not? a. it would be too disruptive to marine life to develop any marine mineral resources b. there is no gold in seawater c. we don't know how to extract minerals from seawater d. it would be too costly and difficult to separate the small amount of gold from the very large amounts of halite and other minerals

In the construction of new housing development, which factor of production can be categorized as land?