If it was in the zoo, the snakes were away from their natural environment. But even if it was in the wild, with the great environmental changes of modern times the snakes might have been "struck dumb" too!
如果是動物園，百步蛇已經脫離原鄉，若在野外，現代大環境的改變，百步蛇恐怕也要闇啞無聲！