On the last Valentine's Day, my father gave my mother a ring. It had a very special design, which twists the ends from the beginning to the end. I was extremely surprised: 

- Wow, I have never seen such a unique ring like that!

My father took a long, rectangular piece of paper, turned one end upside down, and hooked it up to the other end. My father told me to draw a vertical line on this ribbon. I was shocked when my line ended with a starting point. Then my father quizzed me: 

- If I cut along the line with scissors, can you guess what would happen?
- I think it would break in two. 

My father smiled and then cut it. I couldn't believe my eyes that the ribbon didn’t split, it doubled in size. “Similarly, if you cut along a third of the width of the ribbon, it will split into two circles: a big one and a small one,” my father said. He asked if I could explain the phenomenon. I naively replied "Because you glued it with glue, it can't be separated". He laughed and said this is the Mobius ribbon. It is named after the German mathematician August Ferdinand Möbius, who discovered it in 1858. The ribbon that is glued together after flipping the ends to form an endless loop. In mathematics, it is also known as the Mobius surface, one inclined plane, one boundary surface. Depending on the direction of rotation, we have two types of Mobius faces: clockwise and counterclockwise. The feature of this ribbon is that there is no starting point, no end point, thinking two-sided but one-sided. The ring that my father gave my mother is called the Mobius ring. It is modeled after the ribbon Mobius that forms. It conveys loyalty and is a symbol of eternal love, always towards each other. This fateful relationship can't escape anywhere.