A- valve replacement
b- stents
x- heart transplant
The answer is (b.) ecosystem. An ecosystem is all living organism in an area functioning together with nonliving factors of the environment. An Ecosystem is a community of the living organism that includes the producers, the consumers, and the decomposers.
The flow of energy moves through living organisms via the food chain. A food chain is a diagram which shows how every living thing gets energy to live. Plants use the sun, nutrients in the soil and water to generate energy. Herbivores eat the plants to generate energy to survive. Carnivores eat the herbivores to generate energy.
<span>Matter moves through the biosphere by being cycled through various organic and inorganic stages. They are neither created nor destroyed. The biosphere is known as a closed system so no elements can escape. They are continually being recycled. </span>
Answer:
I think it's b but good luck and nice profile pic :D
Answer:
The answer is Bone Marrow
Explanation:hope this help :3.....bye