C438 A prodigious problem

"Alright, this is not something I should be teaching you. You'll know when you grow up, understand?" Seeing Mu Ran's expression turn aggrieved once again, Lei Zhi immediately added, "This matter can only be understood and not told."

Mu Ran looked at him for a while and didn't continue. He shrugged his shoulders and said, "Since you don't want to say it, then I'll go ask big brother Chen Zhen