Problem: - Sulfur in the coal combines with oxygen to form sulfur oxides - The sulfur oxides are released into the atmosphere - The sulfides combine with oxygen in the atmosphere to form sulfur trioxide - The sulfur trioxide reacts with water in the atmosphere to form sulfuric acid, a very strong acid - The sulfuric acid makes the rain acidic - What might be the first step of the process?

A: Coal is burned

Problem: - The sediment breaks down into small particles - Wind or water picks up the sediment - The sediment travels along the same route as the wind or water - The sediment is deposited at new locations by the wind or water - The sediment is picked up again by new wind or water - The sediment travels further - The sediment is deposited again in a new place. What might be the first step of the process?

A: Sediment settles in a place due to gravity

Problem: - The spores fall to the ground - The spores germinate - The spores begin to grow mycelium - The mycelium begin to sprout a bud - A new mushroom is formed. What might be the first step of the process?

A: Spores are dispersed into the air by a mature mushroom

Problem: - Nephrons in the kidney filter the blood - The waste that is filtered out mixes with water - Become urine - Ureters carry urine out of the kidneys. What might be the first step of the process?

A:
Blood carried into kidney by the renal artery