Question

    In habitats across the planet, animals periodically drop everything to walk, fly or swim to a new place. Wildlife such as whales and geese learn migration (迁移) paths by following their parents. Others, including small songbirds, gain the distance and direction of their migration within their genetic (遗传的) code. And some animals use a combination of genetics and culture to guide their migration.

Another group of migrators does not quite fit either model, and researchers have only recently started to figure out how they find their way. Take the Cory's shearwater, an oceangoing sea bird that migrates over the Atlantic every year. The young do not migrate with their parents, so culture cannot explain their journeys. And the exact paths vary wildly from individual to individual, making genetics equally unlikely.

Cory's shearwaters are long-lived, rarely producing young successfully before age nine. This leaves an opening for learning and practice to develop their migration patterns. Researchers call this the "exploration-refinement", and until now it has been hypothetical (假设的) because of difficulties in tracking migratory animals' movements.

But a team of researchers has done that by attaching small geolocators to more than 150 of the birds aged four to nine. They found that younger birds traveled longer distances, for longer periods, and had more diverse paths than older birds. “We finally have evidence of the "exploration-refinement" for migratory birds," says Letizia Campioni, who led the study. Younger Cory's shearwaters are able to fly just as fast as the adults- but they do not, suggesting that the young do more exploring, which gradually fades as they mature and settle into a preferred course.

“Although it may seem less efficient than other strategies, ‘exploration refinement’ could be beneficial to birds and other organisms in a rapidly changing world due to unpredictable man-made changes,” says Barbara Frei. “It might be safer to repeat a behavior that was recently successful than to rely on patterns that were perfected long ago but might no longer be safe.”

1.The first paragraph mainly        .

A.describes animals' habitats B.talks about migration models

C.compares different species D.introduces a tracking technology

2.What does the underlined word "this" in paragraph 3 refer to?

A.The long life of Cory's shearwaters.

B.The way Cory's shearwaters form their migration patterns.

C.The opening for learning and practice.

D.The process scientists track Cory's shearwaters' movements.

3.What docs Letizia Campioni's study find about the younger Cory's shearwaters?

A.They travel as much as adult birds.

B.They move in a predictable manner.

C.They lower the speed for exploration.

D.They look for a course with their parents.

4.What can we conclude from the last paragraph?

A.Man-made changes make migration easier.

B.Animals make a safer journey via a fixed track.

C.Course exploration contributes to birds' adaptability.

D.A combination of strategies assures migration success.

Answer

1.B

2.B

3.C

4.C

【解析】

这是一篇说明文。文章讲述了研究人员最近发现一种不同于一般动物的迁徙模式，以科里的剪水鹱为例，它是一种每年在大西洋上空迁徙的海鸟。研究发现，剪水鹱中，年轻的比年长的走得更远，时间更长，路径也更多样化。这证明了候鸟的“改进探索”的存在，在瞬息万变的世界里，“改进探索”可能对鸟类和其他生物有益。

1.主旨大意题。根据第一段中的Wildlife such as whales and geese learn migration paths by following their parents. Others, including small songbirds, gain the distance and direction of their migration within their genetic code. And some animals use a combination of genetics and culture to guide their migration. (像鲸鱼和鹅这样的野生动物通过跟随它们的父母来学习迁徙路线。其他动物，包括小型鸣禽，在其遗传密码中获得它们迁徙的距离和方向。一些动物利用遗传和文化的结合来指导它们的迁徙。)可知第一段提到像鲸鱼和鹅这样的野生动物及其他动物的迁徙模式，因此第一段主要描述了不同的迁徙模式，故选B项。

2.词句猜测题。根据第三段中的Cory’s shearwaters are long-lived, rarely producing young successfully before age nine. This leaves an opening for learning and practice to develop their migration patterns. Researchers call this the“exploration-refinement”(科里的剪水鹱是长寿的，很少能在九岁之前成功地生产出幼崽。这为学习和实践提供时间，以开发他们的迁徙模式。研究人员称之为“改进探索”)可知划横线的上文提到剪水鹱的长寿的特点及不断开发迁徙模式。因此划横线的this指的是剪水鹱形成迁徙模式的方式。故选B项。

3.细节理解题。根据倒数第二段中的Younger Cory’s shearwaters are able to fly just as fast as the adults—but they do not, suggesting that the young do more exploring(年轻的科里剪水鹱能够飞得和成年剪水鹱一样快，但它们不这样做，这表明年轻剪水鹱会做更多的探索)可知Letizia Campioni所做的研究发现，年轻的科里剪水鹱为了进行探索而降低了飞行速度。故选C项。

4.推理判断题。根据最后一段中的“exploration refinement” could be beneficial to birds and other organisms in a rapidly changing world due to unpredictable man-made changes. It might be safer to repeat a behavior that was recently successful than to rely on patterns that were perfected long ago but might no longer be safe.(“探索改良”可能对迅速变化的世界中的鸟类和其他生物体有益。”“重复最近成功的行为，可能比依赖很久以前已经完善但可能不再安全的模式更安全。”)可知“改进探索”有助于鸟类在瞬息万变的世界里更好得生存下去，因此可推出探索迁徙路线会有助于鸟类的适应性。故选C项。