英语听力:2012-02-12 从南极到北极 From Pole To Pole—12(在线收听

 The strike of a great white shark lasts a mere second. Slowing it down forty times reveals the technique and immense strength of this massive predator. 

 
If surprise fails, there will be a chase. The shark is faster on a straight course, but it can’t turn as sharply as a seal. It’s agility versus power. 
 
Once the seals have finished breeding, the giant sharks will move on. It’s now becoming clear that great whites migrate thousands of miles across the oceans to harvest seasonal abundances in different seas.
  原文地址:http://www.tingroom.com/lesson/yytltsfx/2012/244324.html