<span>The net pressure gradient in the cardiovascular system is created by ventricular contraction.
Hope this helps! :)
</span>
The giant impact theory — the idea that a catastrophic collision about 4.5 billion years ago between Earth and a protoplanet about half Earth's size created a disk of molten rock, gas and debris that consolidated to form the moon — was first set forth in the mid-1970s.
Answer:
The diversity and variations between ecosystems that ultimately links to human existence
Explanation:
Endoskeleton
A. Insects and crustaceans
B. Fish
C. Insects especially the pollinators
D. All vertebrates <span />