In what four months are auroral displays most often seen?

Green mainly.

I am pretty sure the answer is a bay. That sounds right to me. Maybe chestnut too.

June through July and song

When hydrogen is covalently bonded to an electronegative atom.

Sedimentary rock as the majority of the surface of the Earth is covered by veneers of it. Shale is the most common form of sedimentary rock. However the most common rock in the whole earth is igneous...