What does the theory of plate tectonics say about the earth's surface.

a. the earth is one solid piece.
b. the earth is mostly covered in water.
c. the earth is very thick.
d. the earth is broken into many pieces.
thx : )

Plzzz hurry im being timed ! humans, like other organisms, require energy for growth and repair. when cells create atp for energy, carbon dioxide is produced as a waste product. how does the body respond to this process in order to maintain homeostasis? a. the digestive and respiratory systems interact to move carbon dioxide to the lower intestine, where it is transformed into methane. b. the circulatory and digestive systems interact to move carbon dioxide to the stomach, where it to break down food. c. the nervous and urinary systems interact to move carbon dioxide to the kidneys, where it is absorbed into the bloodstream. d. the circulatory and respiratory systems interact to transport carbon dioxide to the lungs, where it is expelled from the body.

Pepsin is an enzyme in the stomach that breaks polypeptides into amino acids. pepsin functions best at a ph of around 1.5. what would be the most likely result if the ph of the stomach were increased to 5

Which is an example of a decomposer? a. bear b. algae c. grass d. bacteria d bacteria