2015年6月大学英语六级真题听力mp3和文本下载(第二套)

　　Section C
　　Directions: In this section, you will hear a passage three times. When the passage is read for the first time, you should listen carefully for its general idea.  When the passage is read for the second time, you are required to fill in the blanks with the exact words you have just heard. Finally, when the passage is read for the third time, you should check what you have written.
　　注意：此部分试题请在答题卡1上作答。
       Why would an animal kill itself? It seems a strange question, and yet it is one that has（26）some people for a long time. The lemming (旅鼠) is one such animal. Lemmings periodically commit mass（27）, and no one knows just why!
      The small（28）, which inhabit the Scandinavian mountains, sustain themselves on a diet of roots and live in nests they make underground. When their food supply is（29） large, the lemmings live a normal, undisturbed life.
      However, when the lemmings' food supply becomes too low to support the population, a singular（30） commences. The lemmings leave their nests all together at the same time, forming huge crowds. Great numbers of the lemmings begin a long and hard journey across the Scandinavian plains, zjourney that may last weeks. The lemmings eat everything in their path, continuing their（31）march until they reach the sea.
      The reason for what follows remains a mystery for zoologists and naturalists. Upon reaching the coast, the lemmings do not stop but swim by the thousands into the surf. Most （32）only a short time before they tire, sink, and drown.
      A common theory for this unusual phenomenon is that the lemmings do not realize that the ocean is such（33）water. In their cross-country journey, the animals must traverse many smaller bodies of water, such as rivers and small lakes. They may （34） that the sea is just another such swimmable（35）. But no final answer has been found to the mystery.