How is plastic made?
Plastic is made from oil, natural gas and even plant oils during refining of these oils into other products like gasoline.  Ethane and propane are created when treated with heat during a refinery process called cracking.  This turns the Ethane and propane into ethylene and propylene which are used with other chemical ingredients to create polymers that are the base of what plastic is made out of.
Instruction: How is plastic made?
Context: 
Response: Plastic is made from oil, natural gas and even plant oils during refining of these oils into other products like gasoline.  Ethane and propane are created when treated with heat during a refinery process called cracking.  This turns the Ethane and propane into ethylene and propylene which are used with other chemical ingredients to create polymers that are the base of what plastic is made out of.