Q: What is the missing first step of the following process: - Rain picks up carbon dioxide as it falls to earth - The rain falls on the soil over the limestone - The carbon dioxide in the rain washes through the soil - The carbon dioxide turns into acid - The acid in the rain gets to the limestone below the soil - The acid dissolves the limestone - Acid continues to erode the limestone with more rain over time - The eroded limestone sometimes forms caves.
A: Limestone is located under the soil

Q: What is the missing first step of the following process: - Aluminium cans are then collected and taken to a treatment plant - At the treatment plant the aluminium is sorted and cleaned - Readied for reprocessing - The aluminum cans go through a re-melt process - Turned into molten aluminium - The molten aluminum is made into large blocks called ingots - The ingots are sent to mills and are rolled out into thin sheets - The rolls are ready to be made into new aluminum products.
A: Aluminium cans are put into a recycling bin

Q: What is the missing first step of the following process: - Release them into the air by process of sporulation - Spores are carried by the wind - Land in a hospitable growing environment - The spores germinate into the soil - The mushroom starts growing - The adult mushroom produce spores of its own to repeat the process.
A: Adult mushrooms produce spores

Q: What is the missing first step of the following process: - Through erosion, the stream cuts into the soil and bedrock - Through continuous erosion, a deep gash is cut through - After many years the river may dry up - A dry ravine is left -
A:
A stream or river must occur