- 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?
Ans: The rain with the high acid content falls.

- Air is pulled into the lungs - Oxygen moves from the lungs into the bloodstream - Air is pushed through the vocal chords - A person talks What might be the last step of the process?
Ans: Other air is pushed out of the lungs into the environment.

- 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?
Ans: The rolls are ready to be made into new aluminum products.

- The salt water is heated - As the saltwater is heated the water becomes a gas - The salt particles sink to the bottom of the container - Gaseous water is piped into another container - Allowed to cool - The salt particles are left behind in the first container What might be the last step of the process?
Ans: The second container contains fresh water.