Lu's Clinic.
"Don't push, don't push, if you haven't been called, why are you trying to squeeze forward?"
"Exactly, Dr. Lu will see everyone in turn, what's the hurry?"
"Bro, I see there are only twenty people in front, so why am I number twenty-five?"
"There are four numbers that aren't given out."
"Why?"
"They say it's for emergencies, infants, and the elderly with high age."
"Well, these numbers are free anyway, and if you're called today and can't be seen, you can move forward tomorrow, so what's the rush?"
"That's true."
"..."
When there's a crowd, it's easy for order to get lost, so Lu Jiu used a queue system.
The numbers are free, serving only to maintain order in the queue, and to ensure those who couldn't be seen one day are prioritized the next.
Inside the clinic, Lu Jiu was instructing a man in his fifties on how to take his medicine.
