The type of energy => Biomass energy
The right answer is vein (it contains blood and has valves).
The infra-cardiac veins of small and medium caliber possess this system of fight against gravity. The valves consist of a dense connective tissue, surmounted by endothelial cells, corresponding to a fold of the intima. They allow blood circulation in the sense organ / heart but prevent venous reflux.
Answer:
they are very similar in what they are made of.
Explanation:
sorry
Answer:
it increased so fast because as more and more came to be, their genes evolved to allow them to adapt to their surroundings and prededators which allowed them to live longer, strive in the envirnoment and make even more babies.
Explanation: