Question

reducing ______ emissions reduces the formation of acid rain. mercury lead sulfur dioxide ozone

Explanation:

Acid rain is mainly caused by sulfur - containing and nitrogen - containing compounds. Sulfur dioxide reacts with oxygen and water in the atmosphere to form sulfuric acid, a major component of acid rain. Reducing sulfur dioxide emissions helps reduce acid rain formation. Mercury, lead, and ozone are not the main precursors of acid - rain formation.

Answer:

sulfur dioxide