"We can rule out that the dogs simply distinguish between the pictures based on a simple cue, such as the sight of teeth," said study author Corsin Muller.
研究作者科辛·穆勒说：“我们可以排除狗只是根据简单的线索来区分图片，比如看到牙齿。”
2
Dogs show their teeth to warn, wag their tails to welcome.
狗露出牙时表示警告，摇摇尾巴则表示欢迎。
3
Curiously, waiting a long time for a small rabbit hunting dogs that actually did not feel sharp teeth, and a dog than a long, gentle tongue.