[Q]: What is the missing first step of the following process:  -  Makes water acidic - Kills fish - Kills the soils in trees - Leaves are also harmed.
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[A]: Acid rain enters the atmosphere and lands


[Q]: What is the missing first step of the following process:  -  Food begins to be processed by the digestive system - The pancreas releases enzymes to aid digestion - Digested food affects the amount of sugar in the blood - The pancreas releases one hormone to lower the blood sugar (glucose) level - The pancreas releases another hormone to raisethe blood sugar (glucose) level.
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[A]: Food enters the body


[Q]: What is the missing first step of the following process:  -  The lungs remove oxygen from the air - Oxygen diffuses from alveoli in the lungs to the bloodstream - Hemoglobin in red blood cells attaches to the oxygen - Red blood cells carry oxygen all around the body - Oxygen diffuses into cells from capillaries.
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[A]: Air goes into the lungs


[Q]: What is the missing first step of the following process:  -  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 - The rolls are ready to be made into new aluminum products.
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[A]:
Aluminium cans are put into a recycling bin