Active muscles demand huge amounts of oxygen, and the circulatory system works hard to provide it. Blood carries oxygen to the muscles. When the body is at rest, blood carries nutrients to the muscles so that they can repair and rebuild themselves. Blood also carries away the waste products that hard-working muscles produce, back out through the lungs to be filtered.
so they Circulatory system xx muscular system :)
Answer:
is the spread of something more widely
Explanation:
The correct answer is: Layer 1, layer 2, and layer 4 in all three regions.
The index fossils are fossils that are commonly used for identifying a geological period of time, and these fossils are also very wide spread, as well as having a rapid evolutionary trends.
By this picture, we can easily see that even though we have rock strata from different regions, the same layers contain the same fossil, and it is a fossil that also is rapidly evolving so has a minor change in each layer.
Small, highly concentrated cell organelles that produce proteins are called <span>ribosomes. Ribosomes can be free-floating or attached to endoplasmic reticulum.</span>
Earths food chain starts with the sun then it goes to producers such as plants that absorbs the sun’s energy to produce their own “food”