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 ma

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

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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【C16】______ roots underground. Some disperse their seeds on winter winds or produce burs full of【C17】______ that get【C18】______ on the fur of passing animals.
     Trees don’t completely stop growing in winter【C19】______ , but they control the growth of their buds and 【C20】______ to the cold and lack of moisture by protecting their buds with scales.
【C5】
选项 A、since
B、when
C、while
D、where
答案C
解析 我们知道连接词while一般用来引导时间状语，表示两个并行但是不同的动作。有时，从这样一个意思可以表示两个对比的动作，表示两种不同的行为和事情或者两种不同的状态。同时，连接词的选择有时还要注意句子之间互相关联的或者修饰的逻辑关系。
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