Several years ago a rare species of bird for some unknown reason .
Several years ago a rare species of bird for some unknown reason .
几年前，因为某种无人知晓的原因，这种稀有的鸟绝迹了。
Several years ago a rare species of bird for some unknown reason .
几年前，因为某种无人知晓的原因，这种稀有的鸟绝迹了。