根据短文内容，从短文后的七个选项中选出能填入空白处的最佳选项。选项中有两项为多余选项。Mass Migration Look up at the sky one autumn da

根据短文内容，从短文后的七个选项中选出能填入空白处的最佳选项。选项中有两项为多余选项。
Mass Migration


Look up at the sky one autumn day and you might see a flock of birds in V-formation. 【小题1】 All summer, they have lived in the north where they made their nests, laid their eggs, hatched, and raised their young. Soon, snow and ice will cover all their northern breeding grounds, so they must migrate south where food is easier to find. It is necessary to create worldwide bird sanctuaries(保护区) before many of these species become extinct（灭绝）.
【小题2】 The Arctic tern travels 10,625 miles from one polar region to the other. This may be the longest migration of any animal on Earth. Not all birds migrate. Some are able to adapt to winter by changing their diets. 【小题3】 For most species, however, it is easier to migrate to climates that are not as severe.
Somehow, migrating birds know exactly where they are going and how to get there. It is amazing to think about how birds are able to return to the same place year after year. 【小题4】 Other scientists believe that migratory birds navigate by following certain coastlines, mountains, and rivers. However they do it, these amazing creatures always arrive in the right place at the right time. In the spring, they return to their nesting grounds up north to lay their eggs and care for their young.
It is important for the people of the world to protect the estuaries (河口)and wetlands . 【小题5】 With so many species of birds’ habitats threatened worldwide, our children may never be able to enjoy the beauty of these migrating wonders.A．These birds stay in the same place all year.B．They are important to endangered species. C．Some birds travel great distances, crossing entire continents and oceans. D．They are flying south where there is warmth and food during the winter.E. Birds fly around the world according to the weather year around year.
F. Some scientists think it is possible for birds to use the stars to find their way.
G. The birds that migrate south in winter return to different places when weather is warm.D

(答案→)D 解析：文章介绍鸟类迁徙的原因和方式，还有一些鸟不用迁徙，为了让鸟类更好迁徙，有必要保护河口和湿地。【小题1】考查句意理解和上下文：根据上文的句子：Look up at the sky one autumn day and you might see a flock of birds in V-formation.可知：它们会向南方飞那里冬天更暖和有食物，所以选D【小题2】考查句意理解和上下文：根据下文的句子：The Arctic tern travels 10,625 miles from one polar region to the other. This may be the longest migration of any animal on Earth.可知：一些鸟要飞很长的距离，穿越大陆和海洋，所以选C【小题3】考查句意理解和上下文：根据上文的句子：Not all birds migrate. Some are able to adapt to winter by changing their diets可知：这些鸟在全年都呆在一个地方，所以选A【小题4】考查句意理解和上下文：根据上文的句子：It is amazing to think about how birds are able to return to the same place year after year.可知：一些科学家认为鸟利用星星找到路是可能的，所以选F【小题5】考查句意理解和上下文：根据上文的句子：It is important for the people of the world to protect the estuaries (河口)and wetlands可知：他们对濒危动物是重要的，所以选B

这个解释是对的