Take a long piece of white paper, paint one side black, then turn one end upside down and stick it into a Mobius belt. Cut the paper tape along the center with scissors. Not only did the paper tape not split in two, but it was cut into a circle twice as long. The newly obtained longer paper circle itself is double-sided, and its two boundaries are not knotted, but nested together. Then cut the paper circle along the center line. This time, you really split it in two. You get two paper circles nested with each other, and the original two boundaries are contained in two paper circles respectively, but each paper circle itself is not knotted. Mobius belt has more bizarre characteristics. Some problems that could not be solved on the plane were actually solved on the Mobius belt. For example, the problem of "glove translocation" that can't be realized in ordinary space: although people's left and right gloves are very similar, they are essentially different. We can't put the gloves on our left hand correctly on our right hand; You can't put the gloves on your right hand correctly on your left hand. No matter how you twist, the left-handed condom is always the left-handed condom, and the right-handed condom is always the right-handed condom! However, if it is moved to the Mobius belt, it will be easy to solve.