input question: What is the missing first step of the following process: - Rain falls - Water is in the area of high elevation - The water creates a stream - The stream moves towards lower elevation - The stream continues along the same path for a long time - The soil and rocks erode where the stream touches them - The stream moves deeper into the soil - The stream is smaller than the eroded area.???
output answer: An area is at a higher elevation than the surrounding area

What is the missing first step of the following process: - They are born and are a baby - The baby grows into a child - Puberty turns the child into an adolescent - The adolescent becomes an adult - An adult becomes an elderly person - The elderly person dies.
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Answer: There is a fetus in the womb

Q: What is the missing first step of the following process: - Water is absorbed through roots - Chloroplast cells in leaves contain chlorophyll - Chlorophyll absorbs energy from sunlight - Energy splits water molecules into hydrogen and oxygen - Oxygen gets released into atmosphere - Hydrogen and carbon dioxide used to create glucose - Glucose is food for plants.
A: Carbon dioxide passes through stomata in the leaves

Question: What is the missing first step of the following process: - The lungs expand - Air is pulled from outside the body, into the lungs - The membranes in the lungs collect oxygen molecules - Oxygen is transferred to red blood cells - Red blood cells distribute oxygen throughout the body -
Answer: The diaphragm contracts

[Q]: What is the missing first step of the following process: - Winter comes and the animal finds a place to hibernate - Over a period of days, the animal's heart rate and breathing rate drop slowly - Electrical activity in the brain almost ceases completely, though some areas remain active - The animal has entered hibernation mode -
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[A]: The animal eats large quantities of food that will be stored as fat

Problem: Given the question: What is the missing first step of the following process: - The pollution negatively affects the water quality - The pollution negatively affects the health of plants and animals - The plants and animals have shorter, less healthy lives - The plants and animals do not reproduce very well - The number of plants and animals decreases over time - The quality of water gets worse and worse as there are no plants or animals to clean it - Eventually there is nothing living in the water and it is unusable -
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The answer is:
Pollution enters natural water sources such as rivers and lakes