Answer: It's not blocked
https://www.khanacademy.org/science/high-school-biology/hs-human-body-systems/hs-body-structure-and-homeostasis/a/tissues-organs-organ-systems
The main purpose of hemoglobin is the transport of OXYGEN and CARBON DIOXIDE
Explanation:
1.The Moon has phases because it orbits Earth, which causes the portion we see illuminated to change. The Moon takes 27.3 days to orbit Earth, but the lunar phase cycle (from new Moon to new Moon) is 29.5 days. The Moon spends the extra 2.2 days "catching up" because Earth travels about 45 million miles around the Sun during the time the Moon completes one orbit around Earth.
2.
An eclipse is the result of the total or partial masking of a celestial body by another along an observer's line of sight. Solar eclipses result from the Moon blocking the Sun relative to the Earth; thus Earth, Moon and Sun all lie on a line. Lunar eclipses work the same way in a different order: Moon, Earth and Sun all on a line. In this case the Earth's shadow hides the Moon from view.Lunar and solar eclipses occur with about equal frequency. Lunar eclipses are more widely visible because Earth casts a much larger shadow on the Moon during a lunar eclipse than the Moon casts on Earth during a solar eclipse. As a result, you are more likely to see a lunar eclipse than a solar eclipse.
3.Why Do We have Seasons?
As the earth spins on its axis, producing night and day, it also moves about the sun in an elliptical (elongated circle) orbit that requires about 365 1/4 days to complete. The earth's spin axis is tilted with respect to its orbital plane. This is what causes the seasons. When the earth's axis points towards the sun, it is summer for that hemisphere. When the earth's axis points away, winter can be expected. Since the tilt of the axis is 23 1/2 degrees, the North Pole never points directly at the Sun, but on the summer solstice it points as close as it can, and on the winter solstice as far as it can.
Why Do the Seasons Change on Earth?
Two things cause the seasons to change. First, the Earth moves around the Sun. Second, the Earth has a tilted axis of rotation.
The Earth spins around an axis. This imaginary line extends from the South Pole to the North Pole. But the Earth’s axis is not vertical. It’s actually tilted at an angle of 23.5°. The planet is always tilted in the same direction as it orbits the Sun.
Protons have a positive charge. The number of protons in a nucleus determines the identity of the atom (element) and this number is called the atomic number.
D. Proton
The organism (Living thing), utilizes energy, can detect changes in the environment it is in, and can rearrange and synthesize chemical compounds.
Some things to remember, Living organisms need to be able to reproduce, obtain energy, usually by eating food in order to work. They need the ability to maintain structure, a body. They need to be able to react to a change, whether it be external or internal. The organism must be able to dispose of waste. Needs the ability to grow and develop. Must be able to move. and finally death. <span />
