英语听力：2012-02-17 从南极到北极 From Pole To Pole—14

（单词翻译）

 All across southern Africa, all animals are journeying for the same reason. Buffalo¹ join the great track. Nowhere else on Earth are so many animals on the move for the same urgent purpose. They are all heading for the swamps of the Okavango, a vast inland delta². At the moment it is dry. But water is coming. The travelers are hampered³ by dangerous dust storms. Mothers and calves⁴ can easily get separated from the main herd⁵. For this pair, sanctuary⁶ lies in a patch of woodland a few miles ahead. They can’t rest until they reach it. The main herd has already got there safely. Finally, the strugglers emerge from the dust. The exhausted⁷ calf⁸ is still blinded by sand. Its mother does everything possible to help it.