input: Please answer the following: What is the missing first step of the following process:  -  Above the oven is a tank of water that is sealed - The tank of water begins to boil above the oven - A the water boils steam is created - The steam is denser than air so it needs a place to go - The steam is forced out of the tank and into a piston - The piston moves up - The valve of the piston closes - The valve on the next piston opens - The steam fills the next piston, driving it up, and the other one down -
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output: A fuel is heated in an oven

Please answer this: What is the missing first step of the following process:  -  The aluminum is collected - Taken to a treatment plant - The aluminum is sorted and cleaned ready for reprocessing - The aluminum is re-melted - Turned into molten aluminum - The aluminum is made into large blocks called ingots - The ingots are sent to mills to be rolled out - The rolled out product is made into new aluminum products.
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Answer: The consumer throws aluminum cans and foil into a recycle bin

Problem: What is the missing first step of the following process:  -  Cells in the pancrease release glucagon - The liver in response turns the glucagon into glucose - And releases it into the blood - The blood sugar levels are restored.

A: The blood sugar drops in a body

Problem: Given the question: What is the missing first step of the following process:  -  The sediment breaks down into small particles - Wind or water picks up the sediment - The sediment travels along the same route as the wind or water - The sediment is deposited at new locations by the wind or water - The sediment is picked up again by new wind or water - The sediment travels further - The sediment is deposited again in a new place.
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The answer is:
Sediment settles in a place due to gravity

input question: What is the missing first step of the following process:  -  The air enters the mouth and nose - The diaphragm contracts - Air fills all the sacks in the lungs - Oxygen passes through the sacks into capillaries - The blood is passed to the blood in the capillaries - The blood carries the oxygen to the heart - The heart pumps the oxygenated blood to the body.???
output answer: You inhale

input question: What is the missing first step of the following process:  -  Falls onto the ground - The acid rain starts scouring rocks - Destroys vegetation - The lack of vegetation alters the surrounding environment.???
output answer:
Acid rain is produced by chemicals that reach into the atmosphere