Answer:
Cetacea it's the correct answer!
The good thing about a dam is that electricity can be created by mechanical means. That does not affect the atmosphere. Storing such production is a different matter.
The bad thing about a dam is that it wreaks havoc on the land where the water is stored behind the dam.
Answer:
assist with flood control
Photosynthesis produces oxygen and water. Photosynthesis is the result of a cycle. Humans use oxygen for respiration, the product produced from human respiration is carbon dioxide. Then plants absorb carbon dioxide from the air and turn it into oxygen with photosynthesis, this goes on and on as a cycle.
