chapter 167 I'm thinking about it

"We'll know after verifying it."

Sun Dasheng squatted down, took out a dagger he carried with him, drew a mark on a cobblestone, and then said, "Let's walk again."

Professor Tan: "Let's go."

This time the three of them walked very carefully. It was probably two minutes later that the three of them stopped at the same place.

"Brother Zhao, you are right, we have been standing still." Sun Dasheng squatted down and saw the marked stone just made.

Professor...