Answer:
color changed.
and the temperature changed.
Explanation:
A- valve replacement
b- stents
x- heart transplant
Answer: Cells
Explanation:
The body has levels of organization that build on each other. Cells make up tissues, tissues make up organs, and organs make up organ systems. The function of an organ system depends on the integrated activity of its organs.
Explanation:
If water did not expand when freezing, then it would be denser than liquid water when it froze; therefore it would sink and fill lakes or the ocean from bottom to top. Once the oceans filled with ice, life there would not be possible.
At least 12 million years ago?