Answer:
Gravity?
Explanation:
These are the things needed for life: water, air, food, light, shelter, and space. It doesn't include gravity.
Answer:
covalent bonds within each strand
Explanation:
The study pushes back the clock on the origin of Earth's water by hundreds of millions of years, to around 4.6 billion years ago, when all the worlds of the inner solar system were still forming. Scientists had suspected that our planet formed dry, with high-energy impacts creating a molten surface on the infant Earth.
Answer: 4.6 billion years.
