Answer:
Bonded to meteorites that hit the Earth
Explanation:
The origin of water on Earth is being linked to the existence of very old meteorites that have been found on Earth. The "Carbonaceous chondrites," which are meteorites, have a similar content to that of seawater. Its isotope levels for hydrogen and nitrogen are similar with Earth's seawater. They're believed to have come from the outer asteroid belt and later on delivered water to Earth after collision.
