Answer:
ponds cooler than 20 °C
Explanation:
There is great effect of temperature on the dissolved oxygen in a pond water,
When the water is hotter it will hold less oxygen but when the water is cold it will holds more oxygen. Therefore, ponds cooler than 20 °C will will have a higher average oxygen concentration.
A. collapsing dust clouds
Answer: It is B
Explanation: I took the test already ;)
