From where did Earth get its water?

Its a question that is so incredibly simple but has a very interesting answer. The water found in Space came from a Solar nebula that gave the Hydrogen. Collapsing stars during the early stages of the universe formed Oxygen and the result was water. There are two theories for water on Earth.

One theory suggests that water came from the many asteroids that impacted the Earth. An asteroid contains 80% water so this could be a reliable theory. Another theory suggests that Earth got water from the above solar nebula. Water travelled through Space interacting with the different forces before finally reaching the Earth and clinging on because of the Earth's gravity.

 Astronomers are still not 100% sure as to where the water truly originated from. The second theory seems to make more sense because the Earth is mainly made of 70% water. Such a lot of water cannot be the result of just asteroids impacting the Earth. Both events happening at the same time makes more sense. The asteroids created craters that could hold the water from the Solar Nebula.

I in-fact have one more theory. Since the Earth is made of mainly Carbon, Oxygen, Helium and
Hydrogen, I believe the asteroids merely left elements that later combined on their own on Earth to form water.

Another fun fact is that there is a large H2O cloud in Space that contains 120 trillion times the amount of water on Earth. The cloud is known to circle a black hole which is known to emit energy in the form of light and electricity.

Thanks for reading!