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.

49. 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. 

50. 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

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

A. Negative                  B. Doubting                  C. Positive             D. Hesitating

52. 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

第二部分  阅读(共两节,满分80分)

第一节:阅读理解(共35小题;每小题2分,满分70分)

阅读下面短文,掌握其大意,然后从21~55各题所给的四个选项(A、B、C、D)中,选出最佳选项,并在答题卡上将该项涂黑。

It has long been known the ancient Egyptian rulers, or pharaohs, were buried with great ceremony and lavish treasures that were to be used in the other world.

Unfortunately, until 1922 no remains of any of the pharaohs or their treasures had ever been found. In that year, however, an archaeologist named Howard Carter and his sponsor, Lord Carnavon, were at last successful. They found the tomb of King Tutankhamen, who was buried 3,200 years ago. King Tut’s tomb was the first fully preserved burial site to be uncovered in Egypt’s Valley of the Kings. The two men found the tomb to contain wonderful treasures. Gold figures and magnificent furniture decorated with gold were found in the myriad of secret rooms and tunnels within the pyramid.

The only disappointment for Howard Carter came when he found that King Tut’s body was nothing but dust. Apparently a mistake had been made when the king’s remains were mummified (使成木乃伊). Carter did, however, find 143 pieces of jewelry within the mummy case, mostly made of gold and precious stones.

Actually, despite all the publicity about the remarkable finds in his tomb, Tutankhamen’s reign (统治时期) as pharaoh was short and relatively uneventful. He died when he was just 18 years old.

There is an interesting story that goes along with King Tut’s tomb. According to legend, a powerful curse was placed in it. This curse was to descend on anyone uncovering Tutankhamen’s burial place. Not very long after the discovery, Lord Carnavon, along with several of the workmen, died suddenly.

1.The subject of this passage is              .

       A.the Valley of the Kings    B.the discovery of King Tut’s tomb

       C.King Tut’s accomplishments   D.Howard Carter, archaeologist

2.Which statement is true according to this article?

       A.Not until King Tut’s tomb was found did people realize that Egyptian pharaohs

   were buried with great ceremony and lavish treasures.

       B.The first grand burial site of the ancient Egyptian rulers was built 3,200 years ago.

       C.Historically, Tutankhamen’s reign was not very much important.

       D.The writer feels it a pity that Lord Carnavon and several of the workmen died

    because of the curse.

3.It seems clear that King Tut        .

       A.was a great military leader      B.thought a great deal of himself

       C.was afraid of dying  D.was killed by his enemies

4.If you have a myriad of something, you have          .

       A.many       B.some C.few   D.several

5.Which of the following can be the best title for the passage?

       A.King Tut’s Tomb     B.The Egyptian Tombs and Treasures

       C.King Tut’s body      D.The First Pharaoh’s Treasures

 B

    Every afternoon in South Korea, when school and work finish, over 100,000 people meet on the Internet to play a game called Lineage. They meet in a virtual(虚拟的) world 500 years in the past. They form teams and fight for justice and money. They are part of one of the Internet's many online gaming communities. The people who play these games are called gamers. Often they meet in 24-hour cafés to play Lineage, as well as other games such as Diablo, StarCraft and Counter Strike. Most gamers just play for fun, but for some people, it can become an obsession (着迷).

    When gaming becomes an obsession it can become dangerous. In Hong Kong, a seventeen-year-old boy died as a result of playing his favourite game in the café where he worked. After working for eight hours, he often stayed at the café and played Diablo II. On some nights he slept for only two hours. In May 2002, he was found unconscious at a computer after playing all night. When he died later in hospital, doctors said it was because he was exhausted.

    In Korea, the dangers can come from other gamers. In the virtual world of Lineage, gamers can create new characters for themselves. High school students can become very powerful fighters and leaders. They play against doctors, businessmen and even members of dangerous gangs. But sometimes things that happen in the game affect real life. Gamers have been beaten up in real life by people they have killed online!

56. How many people play Lineage when school and work are over every day in South Korea?

57. What do people do in the virtual world of Lineage?

58. The online games mentioned in the passage are ________.

59. What does the underlined word “exhausted” mean?

60. What does the passage mainly talk about?

 0  24655  24663  24669  24673  24679  24681  24685  24691  24693  24699  24705  24709  24711  24715  24721  24723  24729  24733  24735  24739  24741  24745  24747  24749  24750  24751  24753  24754  24755  24757  24759  24763  24765  24769  24771  24775  24781  24783  24789  24793  24795  24799  24805  24811  24813  24819  24823  24825  24831  24835  24841  24849  151629 

违法和不良信息举报电话:027-86699610 举报邮箱:58377363@163.com

精英家教网