- Particles in the environment interact with rocks - The particles remove small pieces of the rock each time they touch the rocks - The particles continue to hit, brush against, or grow against the rocks - The rock eventually is broken apart by this contact - The pieces of the rock are now small rocks What might be the last step of the process?
Ans: The rock pieces are worn away into smaller and smaller pieces by the same forces

- An enzyme in saliva begins to break down carbohydrates - Food is squeezed down the esophagus when you swallow - Acid and enzyme in the stomach break the food down - Releases nutrients - Food then pumped into small intestine - Fluid and enzymes from liver and pancreas pumped into small intestine - Help break food into smallest molecules - Nutrients pass through wall of small intestine - Nutrients absorbed into blood stream What might be the last step of the process?
Ans: Unused materials passed into large intestine to become fecal matter.

- Air travels into the body - Air reaches the lungs - The lungs absorb the oxygen from the air - The oxygen is transported by hemoglobin - Red blood cells are made of hemoglobin - Blood has a lot of red blood cells - The heart moves the blood throughout the body What might be the last step of the process?
Ans: Blood can bring the oxygen to different cells in the body.

- Your thermostat senses that the room temperature has fallen below your thermostat setting - Your thermostat sends a signal to your heating system to provide heat for your home - When your oil burner is engaged, heating oil travels from the tank to the burner by way of a pump - Here the oil becomes a fine mist mixed with air - The fuel/air mixture is then injected into the burner where it is ignited in the combustion chamber What might be the last step of the process?
Ans: The warm air is disbursed through vents, hot water through baseboards, or by steam radiators