the answer is 21<span>% oxygen, </span>
No somethings only have one cell. they are called unicellular organisms.
500 million for the first picture and for the text i guess it evolved physical reproductive body cells and parts that makes sexual reproduction change as itself as well as birth due to not only human nature but man made things as well, example: hospitals, medicine, chemicals, etc.
Answer:
Isaac Newton
Explanation:
Isaac Newton discovered that white light is a spectrum of seven colour rays.
Answer:
Pressure with Height: pressure decreases with increasing altitude. The pressure at any level in the atmosphere may be interpreted as the total weight of the air above a unit area at any elevation. At higher elevations, there are fewer air molecules above a given surface than a similar surface at lower levels.In addition, gravity is weaker at the equator due to centrifugal forces produced by the planet's rotation. It's also weaker at higher altitudes, further from Earth's centre, such as at the summit of Mount Everest