[Q]: What is the missing first step of the following process: - As the saltwater is heated the water becomes a gas - The salt particles sink to the bottom of the container - Gaseous water is piped into another container - Allowed to cool - The salt particles are left behind in the first container - The second container contains fresh water.
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[A]: The salt water is heated

[Q]: What is the missing first step of the following process: - Sulfur in the coal combines with oxygen to form sulfur oxides - The sulfur oxides are released into the atmosphere - The sulfides combine with oxygen in the atmosphere to form sulfur trioxide - The sulfur trioxide reacts with water in the atmosphere to form sulfuric acid, a very strong acid - The sulfuric acid makes the rain acidic -
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[A]: Coal is burned

[Q]: What is the missing first step of the following process: - Over long periods of time rain can hit the limestone - And cause a acidic reaction - The limestone will slowly disintegrate - A large gap with be where the limestone was - Result in the cave.
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[A]: Some of the rock in the ground is made of limestone

[Q]: What is the missing first step of the following process: - The cold water forms ice crystals - The ice crystals grow by absorbing surrounding water droplets - Form snowflakes - The snowflakes fall to the ground.
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[A]:
Water in the clouds becomes very cold