Which statement accurately describes the relationship between air pressure, air density, or altitude?
As altitude increases, pressure increases.
As altitude increases, air density increases.
Air pressure and density are lowest at sea level.
Denser air exerts more pressure than less dense air

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This is a typical grassland food web. it is also a small picture of an important cycle on earth: the carbon cycle. describe how the carbon gets into this food web. a) bacteria and fungi, the decomposers, recycle carbon from dead organisms. b) carbon is found in the grass and is passed from one level to the next in this food web. eliminate c) all living things give off carbon dioxide as a by-product of respiration and it is released into the atmosphere. d) plants use carbon dioxide as a reactant in photosynthesis, to make usable chemical energy in the form of a sugar.

This is a biological reaction due to a stimulus. i need this quickly !