2. 外语
  3. Next time you gaze outside 【C1】______ a cold winter day and think how dead everything appears, take a closer look. Nature m

Next time you gaze outside 【C1】______ a cold winter day and think how dead everything appears, take a closer look. Nature m

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问题      Next time you gaze outside 【C1】______ a cold winter day and think how dead everything appears, take a closer look.
     Nature may not be at its 【C2】______ in January and February, but it may be the best time to observe amazing adaptations and appreciate the diversity of life even when the temperature falls 【C3】______ freezing.
     Skunks, chipmunks, and black bears are among the few animals to semi-hibernate during the winter.
     The woodchuck is a true hibernator. Many animals 【C4】______ to escape the cold. Reptiles may migrate several inches down into leaf litter or the mud at the bottom of a pond, 【C5】______ fish may swim and feed below the ice. Other animals stay active throughout the winter months.
     Animal tracks and signs are an excellent 【C6】______ to learn about wildlife in winter. Gnawed bark, active lodges, stray feathers, diggings in the ground, urine or scat, or holes in the ice give clues to activity, whether it’s foraging, hunting for prey, finding shelter, or looking for a mate. Tracks are 【C7】______ by their size and shape, the number of toes, the stride, and the mode of locomotion (walking, bounding, galloping, or wadding).
     Blowing leaves, cones, or seeds along with falling or rolling snow can also 【C8】______ interesting tracks and trails on the snow.
     Tracking conditions 【C9】______ with the type and amount of snow; it’s best to look along the edge of a habitat, such as 【C10】______  a forest meets a field, or near water’s edge. Unmelted and undrifted snow provides the clearest tracks. Watch for bird tracks, too, including wing marks: when tracks stop abruptly, the bird probably took 【C11】______  .
     Evidence of insects is also plentiful during the winter. Many insects, with their variety of adaptations, over winter in one of their developmental (sub-adult) stages as either eggs or pupae and emerge in the spring, Insects also have their own version of hibernation in 【C12】______  weather, a resting stage called diapause. For some insects, the ratio of light to dark may signal them to migrate to stable environments beneath the ground, below the water’s surface, or into deep water.
      Other animals seek protection under the insulating blanket of winter snow. Snow hides prey from 【C13】______  and 【C14】______  dormant plants, insects, and small mammals. Deeper snow requires more energy to move through, but makes it easier for smaller animals to reach buds on tree branches.
     Plants also 【C15】______  to cold weather with a wide variety of survival techniques. Winter weeds that look dead and dry may have live roots underground. Some disperse their seeds on winter winds or produce burs full of seeds that get caught on the fur of passing animals.
【C9】
选项 A、change
B、alter
C、vary
D、switch
答案C
解析 单词vary一般表示在一定的范围内的“变动，波动”。如种类，大小，颜色，价格等不同变化。
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