What is the missing first step of the following process: - Above the oven is a tank of water that is sealed - The tank of water begins to boil above the oven - A the water boils steam is created - The steam is denser than air so it needs a place to go - The steam is forced out of the tank and into a piston - The piston moves up - The valve of the piston closes - The valve on the next piston opens - The steam fills the next piston, driving it up, and the other one down -
Ans: A fuel is heated in an oven

What is the missing first step of the following process: - The water freezes into ice - The cracks expand - Over time the rocks split - The rocks are now in smaller pieces.
Ans: Water gets into cracks in rocks

What is the missing first step of the following process: - Water is put in pipes in the coal-fired steam station - The coal is crushed - The coal is moved into a boiler along with hot air - The water is moving through pipes in the boiler - The steam from the water is blown against a turning mechanism - The force of the steam makes the mechanism turn - The mechanism generates electricity.
Ans: Coal is put in a coal-fired steam station

What is the missing first step of the following process: - The female lays eggs - The eggs are incubated by the parents, by sitting on them, for weeks - The bird hatches from an egg - The parents feed them as the continue to grow - Develop flight feathers - The parents teach them to fly - After learning to fly they leave the nest to live on their own - The next year they breed beginning the cycle again -
Ans: A male and female bird mate