英语听力：2012-02-24 从南极到北极 From Pole To Pole—17（在线收听）

 Their secret is teamwork. Impala are their favourite prey. They start to hunt and the pack splits up. An aerial viewpoint gives a new insight into their strategy. As the dogs approach their prey, they peel off to take up separate positions around their target. They seem to form a cordon around the impala. Moving in total silence, they take up their positions. Those ears can detect the slightest rustle.