It turned out to be a quack

In the courtyard, everyone was looking at Rocco Flanders.
"Dad, you think too highly of him. How can a mere traveling doctor understand Dr. Cui's prescriptions?" The speaker was Tang Yurong. From the moment Rocco Flanders entered the door, she completely looked down on this man.
Cui Lang sneered: "Yurong, you can't say that. What if this gentleman has some unique insights? Regardless of whether it is right or wrong, please tell me first."
In fact, Cui Lang was holding it in. As long as...