What is the missing first step of the following process:  -  The boiler produces steam under high pressure - The steam generated in the boiler flows down into a cylinder - Just ahead of the wheels, pushing a tight-fitting plunger, the piston - The piston is connected to one or more of the locomotive&#x27;s wheels through a kind of arm-elbow-shoulder joint called a crank and connecting rod - As the piston pushes, the crank and connecting rod turn the locomotive&#x27;s wheels and power the train along - An outlet valve opens and the piston pushes the steam back through the cylinder and out up the locomotive&#x27;s chimney -
Ans: Coal is loaded into the firebox

What is the missing first step of the following process:  -  Is trapped - Plant also takes in water and carbon dioxide from the environment - The plant forms glucose - The plant releases oxygen into the atmosphere.
Ans: Sunlight strikes the chlorophyll molecules in the plant

What is the missing first step of the following process:  -  The trees die off - The dead material provides nutrients for more trees - The rising trees provide shelter - And more organisms begin to thrive - The ecosystem known as a forest is made.
Ans: Networks of trees start forming

What is the missing first step of the following process:  -  After a rain, water seeps into cracks and pores of soil and rock - The water percolates beneath the land surface - Some of the water reaches a zone where all the cracks and pores in the rock are already filled with water - Rainwater absorbs some carbon dioxide as it passes through the atmosphere and even more as it drains through soil and decaying vegetation - The water combines chemically with the carbon dioxide - A weak carbonic acid solution is formed - This acid slowly dissolves calcite, forms solution cavities, and excavates passageways -
