The sadness of the Ferris wheel is that no matter how long it turns, it will return to its original point one moment.

The sadness of the Ferris wheel is that no matter what it has experienced, it can only rotate in a certain trajectory and direction.

The sadness of the Ferris wheel carries too much happiness, but I don't know that sadness is behind happiness.

The sadness of the ferris wheel is obviously so sad, but nothing can change it.