Air moves into the lungs when the air pressure in the lungs is lower than the air pressure outside of the lungs. This occurs when the muscels of the diaphragm contract.
You can see this by breathing in and out deeply. When you breath in you can feel your chest being pushed up and out by your diaphragm. The reason the pressure in the chest is lower is that when you breathe in you are increasing the volume of your chest. As there is the same amount of air in your chest the pressure decreases.
Fossil record of the first possible bipeds is the evidence exists that state humans are evolved in Africa. Modern humans arose in Africa at least 250,000 to 300,000 years ago, fossils and DNA are the evidence that reveals. Scientists have been unable to pinpoint a more specific homeland because the earliest Homo sapiens fossils are found all across Africa.
Humans first evolved in Africa, and much of human evolution occurred on that continent. The fossils of early humans who lived between 6 and 2 million years ago come entirely from Africa. Most scientists currently recognize some 15 to 20 different species of early humans found from Africa.
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The answer is carbon dioxide. im 100 percent this is right<span />
It is the third option
Carbon dioxide (CO2) + Water (H20) produces Glucose (C6H12O6) and Oxygen (O2)