Question

Whales, seals and walruses stay warm in cold water because they have a thick layer of blubber. We humans rely on something like blubber—neoprene rubber wet suits—to spend time in cold water. But the thick versions for really icy water are heavy and clumsy. So rather than taking after big marine mammals, what if we could learn from the littler ones, like beavers and otters?

“These animals are quite small and they can’t carry around a thick layer of blubber. So instead they have fur that is evolved to trap air, and this air provides a layer of insulation for them in water.”

Alice Nasto is a graduate student in mechanical engineering at MIT. Scientists have known about this air-trapping insulation mechanism for a long time, but they had not teased out the details of how it works. So Nasto and her colleagues took on the challenge.

“We’re creating these furry samples from these rubbery materials by laser cutting molds and casting these hairy surfaces. And through our approach we can precisely control the spacing of the hairs and the length of the hairs.”

The researchers then created a system to gather data when their pelts (毛皮) entered and moved through a liquid—in this case not water, but silicone oil, which makes it easier to see air bubbles. The key is to keep the pelt’s air layer intact (完好的).

“So when they’re crossing the air water interface, initially their hairy texture is full of air. And then you go into water. How much of the air comes down with you as you’re moving in through the interface. So that’s what this model will tell you.”

They found that the denser the hairs, the more the air gets trapped，which should keep the animal—or potentially the human in a future furry wet suit—warm. The research is in the journal Physical Review Fluids.

“What we would like to work on moving forward is understanding, after you dive into the water, how do you maintain this air layer trapped in your fur. And there’s lots of interesting properties of the fur in nature that we haven’t yet looked at in our model that could help explain how this mechanism might work.”

So for now, cold-water divers and surfers will still emulate seals or sea lions. But the day may come when they’ll more closely resemble otters or beavers.

1.What can make littler mammals keep warm in cold water?

A. An air-trapping insulation mechanism.    B. A thick layer of blubber.

C. A fur that is evolved to trap air.    D. A neoprene rubber wet suit.

2.Nasto and her colleagues have revealed _______________.

A. the denser the hairs, the more the air can be carried with.

B. the way this air-trapping insulation mechanism works.

C. how the air layer trapped in the fur is maintained in water.

D. the existence of the air-trapping insulation mechanism.

3.The passage is most probably taken from ______________.

A. a newspaper    B. a travel book

C. a medical report    D. a science magazine

4.What is the best title for the passage?

A. A Fantastic Layer of Fur    B. An Important Research

C. A Wonderful Mechanism    D. A Graduate’s Challenge

Answer

1.C

2.A

3.D

4.A

【解析】

本文为说明文。主要讲述了小型动物在冬天的时候依靠他们薄薄的皮毛，进化成空气滞留的隔热机理的事，说明皮毛层也是很神奇的。

1.细节理解题。根据文章第二段第二句，“So instead they have fur that is evolved to trap air，and this air provides a layer of insulation for them in water…”及第三段第二句“Scientists have known about this air-trapping insulation mechanism for a long time，but they had not teased out the details of how it works．”没有又厚又浓的皮毛保暖，像海狸这样的小动物会有进化成隔绝空气，尤其冷空气的皮，为它们提供了一层隔热层。而这种空气滞留的隔热机理也正是科学家们所研究的对象。综合归纳可知，它们的毛皮进化成隔绝空气。结合选项，选C（一种进化成隔绝冷空气的毛皮）符合题意，故选C项。

2.细节理解题。根据第七段中的They found that the denser the hairs，the more the air gets trapped，…由此可知，Nasto和他的同事们发现毛发越浓密，更多的空气会进入，结合选项，可知选项A符合题意，故选A项。

3.推理判断题。通读全文可知，本文主要研究的是小型动物是如何在冬日保暖，还涉及到科学家对他们的研究等。由内容可知属于科普文章，应当来自于科学杂志。分析选项A. a newspaper报纸；B. a travel book旅游书；C. a medical repor.医学报告；D. a science magazine科学杂志。可知D项符合题意，故选D项。

4.主旨大意题。根据文章内容．主要讲述了小型动物在冬天的时候依靠他们薄薄的皮毛，进化成空气滞留的隔热机理的事，说明皮毛层也是很神奇的．结合选项可知选A。