Answer:Unconditioned response; conditioned response
Explanation: in classical conditioning ,unconditioned response refers to an environmental stimulus which occurs naturally and automatically and triggers a natural response that has not been learned before , this response is called unconditioned response. Like when you cut an onion you will automatically shed an ear.
Conditioned stimulus is previously neutral stimulus such as a bell which is associated with an unconditioned stimulus which is meat , after this association the conditioned stimulus will start to trigger the same response as unconditioned stimulus , this response is a referred to as a conditioned response.
