英语听力:自然百科 大迁徙 Great Migrations—3(在线收听

 Apprentice killers wait for their taste of the chase. But they're about to learn that "hell has no fury" like a zebra protecting her foal. 

 
Older cheetahs know the value of patience. Soon, the herd will move on. Hungry eyes turn to one of the last-born wildebeest, just learning to kick up its heels. 
 
Serengeti vultures have timed their breeding cycles. So their young can share this bounty. 
 
Five out of six wildebeest calves won't make it through their first year.
  原文地址:http://www.tingroom.com/lesson/zrbaike/2010/259331.html