Someone once said to me that the crows under the world are as black as black,
One day I found a white crow, and I began to suspect that everyone else was a liar, that there were white crows.
Gradually, it was found that the crow's fur had black feathers. Over time, the crow finally faded its white feathers and turned black.
More than 10 years later, I found the crow that has been white, I am a bit stubborn, or take it home to raise, time gradually passed, its white feathers faded again, replaced by a dark feather, this time I really believe that the world is as black as a crow. Never again will there be a white crow.