It contracts on its own without input. The answer is C.
Hope that helped you.
In a pond oxygen is gathered in two ways. One from the air or from the aquatic plants that live in the pond. Oxygen gets dissolved from these when mixed with air and water movement
Answer:
C: new, higher-yield crops
Explanation:
All of the other answers are problems while C is a positive scenario.
Whats your channel called?
This is so hard! Sorry can't help :(
