The atmosphere.
a jelly fish and humans
the ice water
Most plants and animals live in the Sunlit Zone.
Pretty sure that the Pacific is the largest body of water in surface area, but that the Atlantic ocean contains a higher volume of water.
Glaciers hold more than 68% of the world's fresh water, making them the largest reservoir of freshwater on Earth. Oceans contain about 97% of the Earth's water, but much of it is saltwater, which is not suitable for drinking or agriculture.
If you're willing to include water in your definition, the Southern Ocean that surrounds Antarctica contains the most protein -- wildlife -- of any ocean on earth.
atlantic
Ions - atoms with an electrical charge. Actually, pure water is a good insulator, but most naturally-occuring water contains some ions, and will therefore conduct electricity.
The Pacific Ocean. It is a close call with the Pacific and the Caribbean.
the ocean
the layer (of the earth) that contains the most water vapor is the troposphere
The ocean is made of water thus all layers contain the same amount of water.
An ocean really is an ocean because different water forms have different types of water. For example, lakes probably wouldn't be great to drink from because people swim in them. Same with pools, oceans, ect. But stream and rivers wouldn't be so bad because most of the time, they stay really fresh.