A sky map is created by astronomers to identify, name, and plot celestial objects it is a map of the sky made by dividing the celestial sphere into 88 different areas.
C is the answer
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Eastern Europe & the (former) Soviet Union transitioned to a:
Market-based economy.
Oxidation - the breakdown of rock by oxygen and water, often giving iron-rich rocks a rusty-coloured weathered surface.
Erosion,oil spills,pollution,tourism,urban development
