Zu Hang also looked a little hesitant, and then said, "Let's test on the balcony first." Let's see what's going on. As soon as I was about to take out the compass, Cen Heng snatched it and said, "I'll come, I'll come, you can teach me." Seeing him open the box on the outside of the compass, I said, "The compass recognizes the master." "Now he can't lose it, and he won't lose it. I had to return it respectfully to me. I only reported two words, "meridian", no