Q: - Magma cools inside the crust - Magma crystalizes - Lava cools on the surface - Lava crystalizes What might be the last step of the process?
A: Minerals dissolved in water crystlize.

Q: - Coal is loaded into the firebox - The boiler produces steam under high pressure - The steam generated in the boiler flows down into a cylinder - Just ahead of the wheels, pushing a tight-fitting plunger, the piston - The piston is connected to one or more of the locomotive's wheels through a kind of arm-elbow-shoulder joint called a crank and connecting rod - As the piston pushes, the crank and connecting rod turn the locomotive's wheels and power the train along What might be the last step of the process?
A: An outlet valve opens and the piston pushes the steam back through the cylinder and out up the locomotive's chimney

Q: - Aluminium cans are put into a recycling bin - Aluminium cans are then collected and taken to a treatment plant - At the treatment plant the aluminium is sorted and cleaned - Readied for reprocessing - The aluminum cans go through a re-melt process - Turned into molten aluminium - The molten aluminum is made into large blocks called ingots - The ingots are sent to mills and are rolled out into thin sheets What might be the last step of the process?
A: The rolls are ready to be made into new aluminum products.

Q: - People breathe and expel carbon dioxide - Engines produce carbon dioxide - Living things produce waste - Waste decomposes - Decomposition produces methane - Water evaporates - Water vapor joins the atmosphere What might be the last step of the process?
A:
Carbon dioxide, water vapor and methane are greenhouse gases