Problem: - Miners enter the mine - Miners remove the coal from the mine - The coal is placed into carts or on a conveyor belt - The coal is moved up to the surface - The coal is loaded onto a truck - The truck takes the coal to a power station. What might be the first step of the process?

A: A mine is excavated in the side of a mountain

Problem: - Food begins to be processed by the digestive system - The pancreas releases enzymes to aid digestion - Digested food affects the amount of sugar in the blood - The pancreas releases one hormone to lower the blood sugar (glucose) level - The pancreas releases another hormone to raisethe blood sugar (glucose) level. What might be the first step of the process?

A: Food enters the body

Problem: - Put the pot over a source of heat - Turn the heat on - Wait for a few minutes - Begin to observe small bubbles in the water - Wait until the water starts to bubble a lot - Wait until you can see steam rising from the water - Turn the heat source off - Take the pot off of the heat source. What might be the first step of the process?

A: Add water to a pot

Problem: - Some scientists believe that releasing too much carbon dioxide into the atmosphere is one of the causes of global warming - This upsets the balance of the carbon cycle - The ozone layer helps protect us from harmful rays from the sun - It is getting damaged from air pollution such as methane gas from livestock and CFCs from spray cans - Acid rain is created when gasses such as sulfur dioxide get high into the atmosphere - The wind can blow these gasses for miles and then they get washed out of the air when it rains - This rain is called acid rain and can damage forests and kill fish. What might be the first step of the process?

A:
One type of air pollution is the addition of carbon dioxide gas into the air