[Q]: 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.
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[A]: A plant grows near or on a rock

[Q]: What is the missing first step of the following process: - The bird collects bits of sticks and grass - The sticks and grasses are placed between support branches - Leaves, mud and spider webs are added to the sticks - The mud, leaves and webs glue the sticks together - The solid nest supports the eggs -
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[A]: A bird picks a spot high spot, often in a tree

[Q]: 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.
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[A]: The blood sugar drops in a body

[Q]: What is the missing first step of the following process: - They secrete digestive juice 'externally' into the small intestine - There are enzymes for breaking down fats, proteins , and carbohydrates - Digestive juices flows from the pancreas through an excretory duct into the small intestine - When the blood sugar levels rise, as they might after a meal, insulin is released - When blood sugar levels are too low, the pancreas releases glucagon into the bloodstream -
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[A]:
Over 99% of the exocrine pancreas cells produce digestive juices