The answer is B. They bring oxygen from the air into the body.
The lungs don’t produce or release oxygen so it’s not A. or D. The lungs do not transform oxygen into carbon dioxide cause our bodies need oxygen not carbon dioxide so it’s not C. Hope this helps!
Yes Darwin’s theory of natural selection
Answer: c
Explanation: Plants and animals need nitrogen to make proteins but they cannot take it in from the air. Because nitrogen is unreactive as a gas, it has to be transformed into a new molecule. When bacteria in the soil takes nitrogen from the air, it becomes nitrates. Finally, it can move through the food chain in this form.
B, because as energy is move up form the phyramid, energy is lost.