In the tropical deserts of Africa, there lives a kind of short grass. If you pull it up, throw it somewhere, and let it stay there for a few weeks or even months, when you see it again, it will have become a handful of withered and yellow weeds, as if dead. But when you put it in the water, you can see it revive. After a few weeks, it is even a thousand times more beautiful than when you first saw it. People gave it a nice name - desert rose.