input: Please answer the following: What is the missing first step of the following process: - They process it with millions of tiny nephrons - Remove all the waste - The kidneys return the blood back to the body through the renal artery - Send the urine with the waste to the bladder through the ureters.
++++++++++
output: The kidneys receive blood from the renal artery

input: Please answer the following: What is the missing first step of the following process: - They are buried under layers of soil - Pressure builds over time - The remains liquefy - The carbon atoms rearrange to become a new substance.
++++++++++
output: Plants and animals long ago died

input: Please answer the following: What is the missing first step of the following process: - A muscle fiber gets a signal from its nerve - Proteins and chemicals release energy to either contract the muscle or relax it - When the muscles contracts the bones connected to he muscle are pulled closer together - When the muscle relaxes the bones move farther apart.
++++++++++
output: Muscles work by expanding and contracting

input: Please answer the following: What is the missing first step of the following process: - 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.
++++++++++
output:
The thermostat senses that the temperature has dropped