What is a gas station with two greetings and three greetings?

Looking at the gas station, greeting three times is the service principle of the oiler. One plus one means that the employee is refueling the vehicle, and seeing two means that the employee guides the second vehicle to the right tanker when refueling, and greeting three means that the employee who is refueling greets the vehicle waiting for refueling at the gas station. For example, please wait a moment, master, and we will cheer for you right away! ",that is to say, the oiler can't just entertain one car, but also take care of other vehicles.