题目

Migration(迁徙) is defined as regular seasonal(季节性的) movement of birds or animals from one place to another. While quite a few animals are known to migrate, the phenomenon is more often associated with birds. When it comes to migration, one of the reasons is seasonal food scarcity(缺乏). In the northern hemisphere, birds spend summers in higher altitudes(纬度) where food is available in plenty. As the food resources start decreasing with the arrival of winter, they fly to the south. In addition, when the conditions become unfavourable during the winter season, these birds seek shelter in new areas where the conditions are good enough to raise their young ones. How do birds know it's the time to begin their journey? Well, as the days start getting shorter, a bird's brain starts releasing hormones (荷尔蒙), which make the bird start overeating, and become restless(焦躁不安的). As the time of migration approaches, migratory restlessness becomes evident in birds. In case of short­distance migration, the timing is mainly based on the changes in weather and availability of food. How do long­distance migratory birds manage to find their way to their destination? Basically, some of these species use the sun as the guiding points in the course of their journey. In addition, the wind pattern is also known to guide the birds as they begin the most important journey of their life. Unfortunately, migratory birds would meet with threats during their journey. For example, many birds die because they feel too hungry and tired during the long journey. Even natural disasters result in the decrease in the number of the migrating population. Worse still, many migratory birds are hunted by people all along their flyway. Title：Migration of birds Definition moving at a regular  71    from one place to another                   72      l         to find enough   73    to survive the winter l         to find a place with favorable weather to raise    74      Ways of determining the right time to migrate l         The changes in the days' length make the birds' brain release    75   . l         When the weather gets unfavourable or food becomes  76    , they know it's time to migrate. Things guiding their way l         the   77     l         the wind pattern Possible   78      during the journey       l            79     and tiredness l             80     l         human activities 答案：81. He/They would say he/they didn’t want any and hung up the phone.  3’ 回答不完整或语法错误扣1分 82. He begged him to stop smoking.   3’ 漏掉smoking扣1分 83. They became very fond of each other.   2’ 84. To show how Frank affected a 19-year-old yound man (he had never even met).  2’

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