Answer:
gravity
Explanation:
streams erode dirt and rocks, transport the sediment, and redeposit it in new locations shaping the earths surface into a system of stream valleys. streams now flow downhill due to the force of gravity
Advantage: #1 Almost 0 emissions (very low greenhouse gas emissions).
#2 They can be sited almost anywhere unlike oil which is mostly imported
Disadvantage #1 Nuclear plants are more expensive to build and maintain.
#2 Proliferation concerns - breeder reactors yield products that could potentially be stolen and turned into an atomic weapon
Relic Boundary is the correct answer :)
