What percentage of all water is fresh on earth?

3% of earth's water is actually fresh, not salty ocean water

2.5%

While nearly 70 percent of the world is covered by water, only 2.5 percent of it is fresh. The rest is saline and ocean-based. Even then, just 1 percent of our freshwater is easily accessible, with much of it trapped in glaciers and snowfields.

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the answer is "a.) well–developed vascular system."

explanation: