Mugger crocodiles, four metres long, could easily take a single otter. 4米长的恒河鳄 能轻松捕获一只落单的水獭
the world's entire population in a single flock. 仅这一群便集中了世界上所有的花脸鸭
a single egg rested on the top of its feet 一颗躺在它们脚背上的蛋