Final answer:
Water is essential for transportation, temperature regulation, lubrication, and protection in the human body.
Step-by-step explanation:
Water is essential for most body functions. It acts as a transportation vehicle, carrying the body's functional chemicals and allowing chemical reactions to take place. Water also helps regulate internal temperature by minimizing changes due to heat emitted by chemical reactions. Additionally, it functions as a lubricant, shock absorber, and cushion, protecting and lubricating joints and other structures in the body.