英语听力:自然百科 黄石公园的夏天 Yellowstone—17(在线收听

 They are vast smoke plumes. Yellowstone is burning. Throughout the summer, the dry lodgepole pines have become like a tinderbox, and lightening has struck the match. The worst wild fires will burn for weeks. In 1988, a third of Yellowstone burnt in a single summer. Devastation.

 
Animals that depend on these forests will starve this winter. But Yellowstone itself has a longer perspective. Ashes fertilize the soil, and fire opens it up to sunlight. As the forests regenerate, new life finds opportunity.
 
In August, fledgling hummingbirds gorge in fields of fireweed that have risen from the forest's ashes. For them, the summer is already nearly over. They must chase the sun south before winter returns.
  原文地址:http://www.tingroom.com/lesson/zrbaike/2012/273758.html