Q: - Animals and plants die in soft soil or mud - Sediment builds up over the remains - The remains decompose, leaving only trace amounts - The remaining parts over the years are replaced with mineral What might be the last step of the process?
A: A fossil is formed

Q: - An organism dies - Water seeps into the remains - Minerals dissolved in the water form crystals - Crystalized minerals cause the remains to harden What might be the last step of the process?
A: The minerals form a fossil.

Q: - Chemicals like sulfur dioxide and nitrogen are released into the air - These substances rise into the high atmosphere - They react with water and oxygen - This creates a more acidic rain What might be the last step of the process?
A: The rain with the high acid content falls.

Q: - Oxygen enters the body through the mouth or nose - The oxygen travels into the lungs - The oxygen binds to hemoglobin proteins within erythrocytes (red blood cells) - The erythrocytes are pumped through the body by the heart What might be the last step of the process?
A:
All cells receive the oxygen.