The cytoplasm and the nucleus together are known as the protoplasm, the living matter of the cell.
What do you mean by "What is a shooting star, a comet or a meteor burning in our Earth’s Atmosphere?"
edit: ohhhhh you are asking what a shooting star is...
its particles of comets or astoroids/metor enter the atmosphere at very high speeds and burn up
It adds more carbon into the atmosphere
Vein because they have valves to prevent back flow of blood.
My best guess is C not sure tho