Answer
Water's ability to act as a solvent is due to its polarity and ability to make hydrogen bonds, which allows it to interact with via hydration, and, thus, dissolve all kinds of polar molecules.
Further, the fact that it does not interact with lipids allows hydrophobic membranes to form between water-filled spaces. The high heats of fusion and vaporization allow water to have a fairly stable temperature, take heat with it when it evaporates (as in perspiration of animals), and float when ice does form, avoiding the crushing of aquatic creatures which are protected beneath the ice.
Work Step by Step
Review the properties of water and imagine how each helps make life possible/protects life, as well as the molecular properties of water.
