I would say C is the most correct.
In D it depends on what water source you're using. Let's say it is a waterfall, then the source of the water (melting ice or a lake) may disappear in the future.
If you're using underwater "windmills" placed in the ocean, then you would expect it to last a while as the ocean will not disappear in the near future.
Gravity pulling the mass of the atmosphere toward the center of the
earth. Atmosphere includes air, water vapor, etc.
Answer:
What r u trying to ask? you need to put more stuff in your question on here so we can answer it.
Explanation:
Answer:
An element is a pure substance as well, because if we fill up a balloon with just helium gas ,it will only contain helium atoms
