3. what are the two prevailing theories about the origin of water on earth?

3. what are the two prevailing theories about the origin of water on earth?
Answer
Brief Explanations:
The two main theories are that water was delivered by comets and asteroids (exogenous delivery), and that water was present in the materials that formed the Earth (endogenous origin).
Answer:
- Exogenous delivery (by comets and asteroids).
- Endogenous origin (present in Earth - forming materials).