"To be more familiar with the destination countries, I also enrolled in study tours organized by travel agencies specifically for tour guides," he says.

"Trying to satisfy every tourist is something that I have always insisted on doing," he says.

The enthusiasm for his job has seen Cao develop special services for some of his clients, such as the elderly.

When Cao learned that one client with cognitive issues had just had an operation, he took the initiative to rent a wheelchair, and carried the guest on his back up any stairs they encountered during the trip.

In particular, he also plans something special for children attending his tours.

"If there are children in the group, I will prepare a notebook for each of them and ask them to record memorable things during the trip, whether it's writing or drawing," Cao says.

"At the end of each day's itinerary, I will invite them to share their experiences with the group to increase their sense of participation."

Such efforts have ensured that he has zero complaints to his name and, over the course of his career, they have helped him win many honors, such as "model guide" from the China Association of Travel Services, and "gold tour guide" at the 2019 national guide competition.

Cao has also shared his experiences with his colleagues, hosting lectures and training sessions.

In July 2020, when tourism was halted due to the COVID-19 pandemic, he dipped his toe into the waters of the online services market.

Cao started his first livestream on Douyin at the Palace Museum, a landmark that holds special cultural significance to him.

"I thought no one would watch, but more than 40 people followed me," he recalls. "I was more than satisfied."