Answer:
I think its A
Explanation:
Because the reason why airplane have closed windows is because we can't breathe in carbon dioxide when we go up. Of course there is oxygen just not a lot as we go up. Why would there be helium in the air? We would sound weird when we skydive.
Answer:
The mitochondria is the power house of the cell it stores energy for the whole cell. :) hope this helps
Explanation:
If there was not a constant Input of energy into the ecosystem then nothing would have the power to do anything and nothing would be alive. the energy starts with the sun, then goes to plants, then animals that eat the plants, and then the animals that eat those animals, Ect. if this chain reaction did not happen then the plants wouldn't have to power to go through photosynthesis and then we would get no energy. the amount of energy lessen with every chain that it goes through, this is why we get more energy eating plants and why they are healthier.