Answer:
c
Explanation:
serotonin as it has neuro cells which can be fixed changed or duplicated.
Answer: The water cycle also known as the hydrolic cycle describes the always foward rotation above and below the surfaces of the earth. The mass of water on earths surface remains fairly consistant. However, the water splits up into diffrent groups, freshwater, saline water, ice, and atmospheric water. The water can travel between catorgories such as river to ocean or ocean to atmosphere through evaporation, condensation, precipatation, surface runoff and subsurface flow. When water go through these physical process it can change aswell such as being a liquid, solid,and gas. During evaporation it takes water from it surroundings and cools its enviromwnt,
the exchanges in heat fluctuate the climates tempature.
The correct answer is option Covalent bonds.
The water is a molecule formed by the covalent interaction between one oxygen and two hydrogen molecule. The chemical formula of the water is 
. In the water molecule, each hydrogen atom shares an electron with the oxygen. The oxygen is more electronegative so, it pulls the electron towards it, and gains a partial negative charge and the hydrogen gains a partial positive charge. The partial positive charge of hydrogen in one molecule attracts the partial negative charge in other molecule and forms inter molecule hydrogen bonding.
I think it's B right because all the fats!
Becaise multiple kinds of organisms leads to further extended food chains, linking together to make a complex food web.
