The organs are known as Vestigial organs. The evolution from land-dwelling animal to the marine animals has led whales as well as dolphins, to lose hind limbs. The pelvic and leg bone serves no purpose in them and just provide the anchorage to muscles
Water (H
2O) is a polar inorganic compound that is at room temperature a tasteless and odorless liquid, which is nearly colorless apart from an inherent hint of blue. It is by far the most studied chemical compound and is described as the "universal solvent" [17][18] and the "solvent of life".[19] It is the most abundant substance on Earth[20] and the only common substance to exist as a solid, liquid, and gas on Earth's surface.[21] It is also the third most abundant molecule in the universe.[20]
Glaciers cover 10% of land surfaces.
Hope this helps
