Trace fossil because a trace fossil is a fossil of a footprint, trail, burrow, or other trace of an animal rather than of the animal itself.
This exchange process takes place in the aveolus (air sac) inside your lungs by diffusion.
it's from a different concentration gradient
the deoxygenated blood with carbon dioxide diffuse into a aveoli (which is in high concentration) and the aveoli release the oxygen into the blood stream (which is low concentration) therefore the blood will be oxygenated again
How old it is compared to another specimen in relation.
The Bible, and more specifically, the Gutenberg Bible
Brainliest?