"The principle of superposition states that the oldest sedimentary rock units are at the bottom, and the youngest are at the top."
Oldest to youngest: Layer B, Layer C, Layer A
The oldest is always at the bottom, the youngest layer is at the top
I would say D. Osteoarthritis, presbyopia
Answer: because mammals have more complex biological structures; limb regeneration would require sophisticated controls to ensure that limbs and organs don’t grow out of control.
Explanation:
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