Question

the prefix hydro means \water.\ what does the hydrosphere refer to?
the rock part of the earth
the watery part of the earth

Explanation:

The prefix "hydro" means water. So, hydrosphere should relate to water. The rock part of the Earth is lithosphere. Since "hydro" is water - related, hydrosphere is about water on Earth.

Answer:

The watery part of the Earth