C140 Ku

The old man smilingly nodded, praising, "Hm, children can be taught, children can be taught!"

"Xiaoxiao, I won't let you laugh anymore!" Gu Fann looked at the old man in front of him with disgust. However, it was not an easy task to create a tricky problem to stop this guy who was known as the most knowledgeable in the Three Realms. Furthermore, he only had one chance. Otherwise