Problem: - The radiation is aborbed by the Earth - Some of the radiation goes back into space - Some is trapped by the atmosphere - If too much heat is trapped - Global warming occurs. What might be the first step of the process?

A: The sun gives off radiation

Problem: - A signal is sent to the heating system - Heating oil travels from the tank to the burner - The oil becomes a fine mist mixed with air - The oil/air combination is injected into the burner - The burner is ignited in the combustion chamber - The furnace heats the air - The blower sends the heated air through the ducts - The heated air comes out the vents and into the room. What might be the first step of the process?

A: The thermostat senses that the temperature has dropped

Problem: - The stomach churns the food - With the aid of stomach acids - The food becomes a thick liquid - Is then passed to the small intestine. What might be the first step of the process?

A: Food leaves the esophagus and enters the stomach

Problem: - Waves have energy that pushes the water and sediment - The sediment can help erode land like sandpaper - Water washes the sediment back - Some sediment is left as sand. What might be the first step of the process?

A:
Waves hit the coast