In which regions is soil erosion very difficult to revert?

Describe the role of photosynthesis and respiration in the carbon cycle.

Why does the moon have extreme temperature variations,ranging from $-190\,^{\circ}C$ to $110\,^{\circ}C$,even though it is at approximately the same distance from the sun as the Earth?

Describe the various steps and processes involved in the nitrogen cycle. Also,explain the cycling of nitrogenous compounds in this cycle.

$(i)$ In what form do plants utilize nitrogen?
$(ii)$ Why do they need nitrogen?

List the importance of oxygen gas and ozone gas present in the atmosphere.