Question

    A breathtaking trick potentially left over from our ancestors might be found in us — the ability to sense oxygen through our skin.

Amphibians, animals such as frogs that can live both on land and in water, have long been known to be capable of breathing through their skin. In fact, the first known lungless frog that breathes only through its skin was discovered recently in the rivers of Borneo.

Now the same oxygen sensors found in frog skins and in the lungs of mammals (哺乳动物) have unexpectedly been discovered in the skin of mice.

“No one had ever looked,” explained Randall Johnson, a biologist researcher.

Mice and frogs are quite distant relatives, so the fact they have these molecules (分子) in common in their skin suggests they might well be found in the skin of other mammals, such as humans.

“We have no reason to think that they are not in the skin of people too,” Johnson said.

These molecules not only detect oxygen, but help increase levels of vital red blood cells, which carry oxygen around the body. Normal mice breathing in air that is 10 percent oxygen—a dangerously low level similar to conditions at the top of Mount Everest, and about half that of air at sea level. However, mice that had the oxygen sensor HIF-1a genetically removed from their skin failed to produce this hormone (荷尔蒙) even after hours of such low oxygen.

These findings, if they hold true in humans, suggest one could raise the level of oxygen circulating inside the body. This could help treat lung diseases and disorders such as anemia (贫血症) without injecting drugs, which make up a multibillion-dollar market, Johnson said.

Athletes also often try to get more oxygen delivered to their muscles in order to improve their performance. They often do this by training at high altitudes or in low-oxygen tents. The new study suggests they might want to expose their skin as well as breathing in low-oxygen air to improve their performance. “It’s hard to say what exactly might be done, however—there’s a lot we don’t know yet,” Johnson explained.

The scientists detailed their findings in the April 18 issue of the journal Cell.

1.Which of the following statements is TRUE according to the passage?

A.Johnson believes that Oxygen sensors also exist in human skin.

B.People have to surf the Internet to read detailed findings.

C.It has been proved that these findings help treat lung diseases.

D.It has long been expected oxygen sensors exist in mice’s skin.

2.One of the functions of the molecules mentioned above is _______.

A.carrying oxygen around the body B.improving athletes’ performance

C.detecting oxygen D.increasing level of oxygen

3.What is Johnson’s attitude to the application of the findings to the athletes’ training?

A.Negative B.Doubting

C.Positive D.Hesitating

4.The best title of the passage may be _______.

A.Great Findings Benefits Athletes A Lot

B.Frogs And Mice Are Distant Relatives

C.First Known Animal Breathes Through Skin

D.Humans Might Sense Oxygen Through Skin

Answer

1.A

2.C

3.C

4.D

【解析】

本文是说明文。科学家们发现人体皮肤是氧气传感器，皮肤中的分子可以检测到氧气，还能帮助增加红细胞的水平，这样可以将氧气输送到全身各处。这一研究发现可以用于治疗肺部疾病和贫血症等疾病，也可以运用于运动员的训练中。

1.细节理解题。根据第六段”‘We have no reason to think that they are not in the skin of people too,’ Johnson said.（约翰逊说：“我们没有理由认为它们不在人们的皮肤里。）”可知，约翰认为人体皮肤里也有这种能检测到氧气的分子，皮肤成为了氧气传感器。故选A项。

2.细节理解题。根据第七段中“These molecules not only detect oxygen, but help increase levels of vital red blood cells, which carry oxygen around the body.（这些分子不仅能检测到氧气，还能帮助增加非常重要的红细胞水平，而这可以将氧气输送到全身各处。）”可知，这些分子的其中一个作用是检测到氧气。故选C项。

3.推理判断题。根据倒数第二段中 “The new study suggests they might want to expose their skin as well as breathing in low-oxygen air to improve their performance. “It’s hard to say what exactly might be done, however—there’s a lot we don’t know yet,” Johnson explained.（新的研究表明，他们可能想要暴露他们的皮肤在空气中，呼吸低氧空气，以提高他们的成绩。）”可以推断，Johnson对于研究的发现运用到运动员的训练中是持肯定的态度，只是认为有更多的东西还有待发现。故选C项。

4.主旨大意题。文章第一段中提到“the ability to sense oxygen through our skin”；科学家们发现人体可以通过皮肤呼吸到氧气，人体皮肤是氧气传感器。皮肤中的分子可以检测到氧气，还能帮助增加红细胞水平，将氧气输送到全身各处。因此文章的标题应为“人类可以通过皮肤感知氧气”。故选D项。