1, the palm of the left hand is downward, and a rubber band is put on the index finger of the left hand. 2. Grasp the lower end of the rubber band with the right hand and rotate the rubber band in the direction of the middle finger. 3. Put the rubber band around the middle finger from below to above the middle finger, further pull the rubber band and put it on the index finger. 4. Hold the front end of the left index finger with the right hand and completely block the index finger. Tip: You can ask the audience to hold your index finger with one hand to ensure that the exit of the rubber band is sealed. 5. Bend the middle finger and loosen a rubber band. It seems that the rubber band wound around the left index finger twice, and the front end of the finger was sealed, but the rubber band escaped. Do you know that?/You know what?