The domestication of plants allowed humans to found the first permanent settlements because food supplies became more a. varied b. stable c. necessary d. expensive

Explain the cause for movement river valley civilization to early industrial centers

What is the result of the greenhouse effect? a. heat is deflected from the atmosphere. b. heat is released from the atmosphere. c. heat is kept in the atmosphere. d. plants are able to grow in the tropics where the air is the heaviest.

The earth's internal process which drives seafloor spreading is