Final answer:
Operators might be alerted by auditory signals, visual signals, or digital notifications on a control panel when the first return is about to occur in an engineering or technical context.
Step-by-step explanation:
The question 'What will alert the operator that the first return is about to occur?' seems to refer to a concept in an engineering or technical field, possibly related to automation, manufacturing, or process control. In such contexts, the first return could refer to the point at which a machine or system completes its first operational cycle and is about to start again. Operators might be alerted by various means, which could include auditory signals like buzzers or alarms, visual signals such as flashing lights, or digital notifications on a control panel or user interface. These alerts are designed to inform the operator of the system status and ensure the process is monitored for efficiency, safety, and quality control.