C
Dangerous Sports
Around the world more and more people are taking part in danger ous sports and activities．Of course, there have always been people who have looked for adventure—those who have climbed unknown parts of the world or sailed in small boats across the greatest oceans．Now, however, there are people who seek an immediate thrill, a risky activity, which may only last a few minutes or even seconds．
I would consider bungee jumping to be a good example of such an activity．You jump from a high place（perhaps a bridge or a hot-air balloon） 200 meters above the ground with an elastic（有弹性的） rope tied to your feet．You fall at up to 150 kilometers an hour until the rope stops you from hitting the ground．It is said that about 2 million people around the world have now tried bungee jumping. Other activities which most people would say are as risky as bungee jumping include jumping from tall buildings and diving into the sea from the top of high cliffs.
　　Why do people take part in such activities as these? Some psychologists suggest that it is because life in modern societies has become safe and boring．Not very long ago, people’s lives were constantly in danger. They had to go out and hunt for food, diseases could not easily be cured, and there was a continuous battle for survival．
Nowadays, according to many people, life offers little excitement．They live and work in comparatively safe environments; they buy food in shops; there are doctors and hospitals to look after them if they become ill．The answer for some of these people is to look for danger in activities such as bungee jumping．
65．The best title for the text is          .
A．Dangerous Sports: What and Why
B．The Boredom of Modern Life
C．Bungee Jumping: Is It Really Dangerous.
D．The Need for Excitement
66．More and more people today           .
A．are tying activities such as bungee jumping
B．are climbing the highest mountains
C．are coming close to death in sports
D．are looking for adventures such as traveling into unknown places
67．The writer of the text has a        attitude towards dangerous sports.
A．positive    B．negative    C．neutral（中立的）  D．nervous

Bungee jumping is an activity about jumping from a tall structure while connected to a large elastic cord(有弹性的绳子). The tall structure is usually a fixed object, such as a building, bridge or crane; but it is also possible to jump from a movable object, such as a hot-air balloon or helicopter, that has the ability to stay over one place on the ground; fixed-wing aircraft are unsuitable because they only stay high when moving quickly forward.

When the person jumps, the cord stretches to absorb (吸收)the energy of the fall, then the jumper flies upwards again as the cord jumps back. The jumper oscillates(摆动)up and down until all the energy is used up.

The word bungee first appeared around 1930 and was the name for a rubber eraser. The first modern bungee jumps were made on 1 April 1979 from the 250-foot Clifton Suspension Bridge in Bristol, by David Kirk, Chris Baker and Alan Weston of the Dangerous Sports Club. The jumpers continued with jumps in the US from the Golden Gate and Royal Gorge bridges, spreading the concept worldwide. By 1982 they were jumping from mobile cranes and hot-air balloons. Later they put on commercial(商业的)shows, which began in 1986.

As with any sport, injuries can still happen, and there have been deaths. A relatively common mistake in the cases that may cause death is to use a cord that is too long. The cord should be fully shorter than the height of the jumping place to allow it room to jumper either starts to slow down or keeps speeding up depending upon the speed of falling.

1.Which of the following is NOT suitable for bungee jumping?

A．The fixed-wing aircraft                   B．The helicopter

C．The hot-air balloon                      D．The mobile crane

2.In the second paragraph, the author tells_________________.

A．who suits bungee jumping

B．the principle of bungee jumping

C．the material used for bungee jumping

D．the danger of bungee jumping

3.According to the last paragraph, the safety of the jumpers depends mainly on________.

A．the weight of the jumper

B．the height of the jumping place

C．the length of the cord

D．the speed of the falling

4.The purpose of writing this passage is to__________.

A．teach people how to carry out a bungee jumping

B．remind people of the danger of bungee jumping

C．advise people not to take the risk of bungee jumping

D．introduce some knowledge about bungee jumping

Which animal has the fastest snapping jaw (颚)? If you're guessing a shark or perhaps a larger animal, you'll have to think smaller. The trap­jaw ant, which lives in Central and South America, moves its mouth parts at 35 to 63 meters per second. Another way to think about this is that the ant's jaws close at 125 to 233 kilometers per hour. That's 2, 300 times faster than the blink of an eye.

Scientists were able to measure the amazing jaw speed using high­speed video techniques. Sheila Patek, a biologist, says the key is that the jaws have a springy (有弹性的) system, which is critical in getting explosive (爆发性的) speeds.

Consider a bow and arrow. If you try to throw an arrow with your arm, it won't go very far. If you use a bow, elastic energy stored in the bow is released almost instantly when you release the arrow with your finger or a latch. The combination of the springy bow and latch mechanism is what makes the arrow zoom through the air.

Maybe even more amazing than how fast these ants grab food or even enemies is how they use this same energy to move. As the ant closes its jaws, it uses them to push off the ground—all faster than the eye can see without slow motion video. A snap of the jaw can send an ant up to 8.3 centimeters into the air. That's like someone who is 1.7 meters jumping 13 meters high! Not only can they quickly escape from enemies, but often a group of ants will start jumping all at once. It would be hard for their enemies to grab just one.

People have suspected the ants used their jaws to jump for over a century, but could only prove it with today's modern video equipment.

1.The fast speed of the trap­jaw ant's jaw lies in ________.

2.The passage uses “a bow and arrow” as an example to show ________.

3.Which of the following may amaze the scientists most?

4.According to the passage, the trap­jaw ants' jaws keep them safe because ________.

She took up skating at age 85, made her first movie appearance at age 114, and held a concert in the neighborhood on her 121st birthday.

　　    When it comes to long life, Jeanne Calment is the world’s recordholder. She lived to the ripe old age of 122. So is 122 the upper limit to the human life span（寿命）? If scientists come up with some sort of pill or diet that would slow aging, could we possibly make it to 150－or beyond?

　　    Researchers don’t entirely agree on the answers. “Calment lived to 122, so it wouldn’t surprise me if someone alive today reaches 130 or 135, ”says Jerry Shay at the University of Texas.

　　    Steve Austad at the University of Texas agrees. “People can live much longer than we think, ”he says. “Experts used to say that humans couldn’t live past 110. When Calment blew past that age, they raised the number to 120. So why can’t we go higher? ”

　　    The trouble with guessing how old people can live to be is that it’s all just guessing. “Anyone can make up a number, ”says Rich Miller at the University of Michigan. “Usually the scientist who picks the highest number gets his name in Time magazine. ”

　　    Won’t new anti-aging techniques keep us alive for centuries? Any cure, says Miller, for aging would probably keep most of us kicking until about 120. Researchers are working on treatments that lengthen the life span of mice by 50 percent at most. So, if the average human life span is about 80 years, says Miller, “adding another 50 percent would get you to 120. ”

　　    So what can we conclude from this little disagreement among the researchers? That life span is flexible（有弹性的）, but there is a limit, says George Martin of the University of Washington. “We can get flies to live 50 percent longer, ”he says. “But a fly’s never going to live 150 years. ”Of course, if you became a new species （物种）, one that ages at a slower speed, that would be a different story, he adds.

　　    Does Martin really believe that humans could evolve （进化）their way to longer life? “It’s pretty cool to think about, ”he says with a smile.

1. What does the story of Jeanne Calment prove to us?

A．People can live to 122.

B．Old people are creative.

C．Women are sporty at 85.

D．Women live longer than men.

2. According to Steve Austad at the University of Texas, ______.

A．the average human life span could be 110

B．scientists cannot find ways to slow aging

C．few people can expect to live to over 150

D．researchers are not sure how long people can live

3. Who would agree that a scientist will become famous if he makes the wildest guess at longevity?

A．Jerry Shay.　                           B．Steve Austad

C．Rich Miller　                           D．George Martin

4. What can we infer from the last three paragraphs?

A．Most of us could be good at sports even at 120.

B．The average human life span cannot be doubled

C．Scientists believe mice are aging at a slower speed than before.

D．New techniques could be used to change flies into a new species

完形填空（共20小题；每小题1.5分，满分30分）阅读下面短文，掌握其大意，然后从1—20题各题所给的四个选项（A、B、C和D）中，选出可以填入空白处的最佳选项。

Throughout history man has had to accept the fact that all living things must die. But people now live longer than they   1  . Yet, all living things still show the   2   of aging, which will eventually   3  death.

Aging is not a disease, but as a person passes maturity (成熟期), the cells of the body and the  4 they form do not function as well as they  5  in childhood and teenage years. The body provides less  6   against disease and is more  7  to have accident.

A number of related causes may   8   aging. Some cells of the body have a fairly long life, but they are not   9 when they die. As a person ages,   10  of brain cells and muscle cells decreases.   11  body cells die and are replaced by new cells. In an aging person the   12  cells may not be as workable or as capable  13   growth as those of a young person.

Another  14   in aging may be changes within the cells  15  . Some of the protein chemicals in cells are known   16  with age and become less elastic (有弹性的). This is why the skin of old people wrinkles (皱纹) and   17 . This is also the reason why old people   18  in height. There may be other more important chemical changes in the cells. Some complex cell chemicals, such as DNA and RNA, store and   19  information that the cells need． Aging may affect this  20 and change the information-carrying molecules so that they do not transmit the information as well.

1. A．would                    B．be used to            C．used to               D． used

2. A．function              B．effect                                          C．affect             D． sign

3.    A．lead in             B．give in                 C．run into              D． result in

4.    A．hands             B．feet                    C．heart                 D． organs

5.    A．do                B．has done            C．did                   D． had done

6.    A．energy            B．protection          C．vigor              D． power

7.    A．likely              B．probable            C．possible              D． alike

8.    A．attend to           B．contribute to       C．add to               D． devote to

9.    A．replaced           B．reborn               C．recovered         D． surrendered

10. A．a number          B．the amount        C．the number        D． a great deal

11. A．The others        B．The other         C．Another            D． Other

12. A．old                B．left                 C．new               D． other

13. A．to                  B．for                 C．of                 D． in

14. A．factor              B．effect               C．reason              D． element

15. A．for themselves    B．of themselves   C．themselves       D． on their own

16.   A．change              B．to have changed  C．to change         D． to be changed

17. A．hangs loose       B．hangs loosely       C．is hanging loosely D． is hanging loose

18. A．increase            B．shrink               C．lengthen            D． decrease

19. A．pass away         B．pass by             C．pass off            D． pass on

20. A．improvement      B．procession         C．approach          D． process