input: Please answer the following: 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.
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output: Acid rain is produced by chemicals that reach into the atmosphere

Please answer this: What is the missing first step of the following process: - The sound waves hit an object - Echoes are produced - The echo returns to the bat's ears - The bat hears the echo - The bat can figure out where the object is located.
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Answer: The bat sends out sound waves from their mouth or nose

Problem: What is the missing first step of the following process: - Waste enters the kidneys - A processing moment in the kidneys let waste and fluid pass - Prevents larger molecules to pass - Fluid goes back to the bloodstream - Bad waste is removed - The final product is turned into urine.

A: Fluid

Problem: Given the question: What is the missing first step of the following process: - The pancreas creates juices that help digest food - The pancreas releases the juices into the stomach - Trypsin and chymotrypsin digest protein - Insulin is produced to move glucose from the blood - The enzymes begin producing again.
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The answer is:
The pancreas detects chemical changes in the stomach

input question: What is the missing first step of the following process: - The sediment rolls down hill towards a river - The heavy items sink to the bottom - The lighter items float on the top and in convection cycles - As the river flows the sediment is moved - The sediment gets dumped through tributaries into lakes and the ocean - The sediment keeps moving around the world in convection currents.???
output answer: Sediment becomes loose from the rest of the soil

input question: What is the missing first step of the following process: - The plant roots begin to grow - Break apart the rock - The plant acids dissolve parts of the rock - The rocks are broken into more and more pieces - Erosion starts to occur.???
output answer:
A plant grows near or on a rock