More and more people take part in marathons these days – over 30,000 people will run the London Marathon this weekend, for instance. But it’s not just the 26 miles and 385 yards that could be a daunting prospect. “I have to admit to being completely frustrated by the blocking and for 18-19 miles was just keeping away from people and being held up,” one participant grumbled after the 2012 London Marathon. “I had to overtake a lot of people and ended up with bruised（淤肿的）forearms from all the elbows,” said another.
How do such crowding problems arise, and could they be reduced? Some researchers believe that we can find the answers through a more familiar system in which jams appear – road traffic flow. Martin Treiber, of the Technical University of Dresden in Germany, has previously developed models for traffic flow. One of the first attempts to model traffic flow was made in the 1950s by James Lighthill and his collaborator Gerard Whitham of Manchester University. They considered the traffic as a kind of liquid flowing down a pipe, and looked at how the flow changes as the fluid gets denser(浓稠). At first the flow rate increases as the density increases, since you simply get more stuff through in the same period of time. But if the density becomes too high, there’s a risk of jams, and the flow rate drops sharply.
Treiber’s model of a marathon uses this same principle that the flow rate first increases and then decreases as the density of runners increases, thanks to an sudden switch from free to crowded flow. He assumes that there is a range of different preferred speeds for different runners, which each maintains throughout the race. With just these factors, Treiber can calculate the flow rate of runners, knowing the “carrying capacity”(承载能力)at each point on the route.
This allows Treiber to figure out how blocking might depend on the race conditions – for example, for different starting procedures. Some marathons start by letting all the runners set off at once (which means those at the back have to wait until those in front have moved forward). Others assign runners to various groups according to ability, and let them start in a series of waves.
Treiber has applied the model to the annual Rennsteig half-marathon in central Germany, which attracts around 6,000 participants. The traditional route had to be changed in 2013, because the police were no longer willing to close a road to ensure that runners could cross safely. It could pass either over a 60m wooden bridge or through a tunnel. Treiber used his model to predict the likely blocking caused in the various options. The model predicted that a mass start would risk an overload of runners if the bridge were to be used. Only by moving the starting point further back from the bridge could the danger be avoided – and even then, if some of the numbers assumed in the model were only slightly inaccurate, there was still a risk of jams at the bridge. On the other hand, no dangerous blocking seemed likely for the tunnel route. The run organizers consulted Treiber’s team, and eventually chose this option.What is the worst thing while running a marathon?
| A．The long distance. |
| B．Too many participants. |
| C．The dangerous blocking. |
| D．Serious injuries in forearms. |
Which of the following statements is true?
| A．James Lighthill is the first expert trying to model traffic flow. |
| B．The denser the flow is, the faster the flow rate becomes. |
| C．The flow rate increases in the beginning because fewer people passed together. |
| D．The flow rate increases first and then decreases later when the flow is too denser. |
What is NOT true about the Rennsteig?
| A．It has much less participants than the London Marathon in 2014. |
| B．It has a shorter distance than the London Marathon. |
| C．The route was changed because the traditional one is not safe any longer. |
| D．The participants running this marathon will pass a tunnel because this choice is safer. |
What’s the main idea of the passage?
| A．Make a comparison between marathon and road traffic. |
| B．Running a marathon is somewhat dangerous if it is not well organized. |
| C．Introduce a new technology to solve the blocking problem in marathon. |
| D．Some advice for people who are to run a marathon. |
Honey from the African forest is not only a kind of natural sugar, it is also delicious.
Most people, and many animals, like eating it. However, the only way for them to get that honey is to find a wild bees' nest and take the honey from it. Often, these nests are high up in trees, and it is difficult to find them. In parts of Africa, though, people and animals looking for honey have a strange and unexpected helper - a little bird called a honey guide.
The honey guide does not actually like honey, but it does like the wax in the beehives (蜂房). The little bird cannot reach this wax, which is deep inside the bees' nest. So, when it finds a suitable nest, it looks for someone to help it. The honey guide gives a loud cry that attracts the attention of both passing animals and people. Once it has their attention, it flies through the forest, waiting from time to time for the curious animal or person as it leads them to the nest. When they finally arrive at the nest, the follower reaches in to get at the delicious honey as the bird patiently waits and watches. Some of the honey, and the wax, always fall to the ground, and this is when the honey guide takes its share.
Scientists do not know why the honey guide likes eating the wax, but it is very determined in its efforts to get it. The birds seem to be able to smell wax from a long distance away. They will quickly arrive whenever a beekeeper is taking honey from his beehives, and will even enter churches when beeswax candles are being lit.Why is it difficult to find a wild bees' nest?
| A．It's small in size. | B．It's hard to recognize. |
| C．It's covered with wax. | D．It's hidden in trees. |
What do the words "the follower" in Paragraph 2 refer to?
| A．A bee. | B．A honey seeker. | C．A bird. | D．A beekeeper. |
The honey guide is special in the way ________.
| A．it goes to church | B．it gets its food |
| C．it sings in the forest | D．it reaches into bees' nests |
What can be the best title for the text?
| A．Wild Bees | B．Wax and Honey |
| C．Beekeeping in Africa | D．Honey-Lover's Helper |
Welcome to one of the largest collections of footwear (鞋类) in the world that will make you green with envy. Here at the Footwear Museum you can see exhibits (展品) from all over the world. You can find out about shoes worn by everyone from the Ancient Egyptians to pop stars.
| Room 1 The celebrity (名人) footwear section is probably the most popular in the entire museum. Stared in the 1950s there is a wide variety of shoes and boots belonging to everyone from queens and presidents to pop stars and actors! Most visitors find the celebrities’ choice of footwear extremely interesting. |
Room 2 Most of our visitors are amazed and shocked by the collection of “special purpose” shoes on exhibition here at the Museum of Footwear. For example, there are Chinese shoes made of Silk that were worn by women to tie their feet firmly to prevent them from growing too much! |
| Room 3 As well as shoes and boots, the museum also exhibits shoe shaped objects. The variety is unbelievable. For example, there is a metal lamp that resembles a pair of shoes, and Greek wine bottles that look like legs! |
The Footwear Library People come from all over the world to study in our excellent footwear library. Designers and researchers come here to look up information on anything and everything related to the subject of footwear. |
Where would you find a famous singer’s shoes?
| A．Room 1. | B．Room 2. |
| C．Room 3. | D．The Footwear Library. |
All exhibits in each room _____.
| A．share the same theme |
| B．have the same shape |
| C．are made of the same material |
| D．belong to the same social class |
Which of the following is true according to the text?
| A．Room 2 is the most visited place in the museum. |
| B．Researchers come to the Footwear Library for data. |
| C．The oldest exhibits in Room 1 were made in the 1950s. |
| D．Room 3 has a richer variety of exhibits than the other two. |
The purpose of the text is to get more people to _____.
| A．do research | B．design shoes |
| C．visit the museum | D．follow celebrities |
Without proper planning, tourism can cause problems. For example, too many tourists can crowd public places that are also enjoyed by the inhabitants of a country. If tourists create too much traffic, the inhabitants become annoyed and unhappy. They begin to dislike tourists and to treat them impolitely. They forget how much tourism can help the country’s economy. It is important to think about the people of a destination country and how tourism affects them. Tourism should help a country keep the customs and beauty that attract tourists. Tourism should also advance the well-being (health and happiness) of local inhabitants.
Too much tourism can be a problem. If tourism grows too quickly people must leave other jobs to work in the tourism industry. This means that other parts of the country’s economy can suffer.
On the other hand, if there is not enough tourism, people can lose jobs. Businesses can also lose money. It costs a great deal of money to build large hotels, airports, air terminals, first-class roads and other support facilities needed by tourist attractions. For example, a major international-class tourism hotel can cost as much as 50 thousand dollars per room to build. If this room is not used most of the time, the owners of the hotel will lose money.
Building a hotel is just a beginning. There must be many support facilities as well, including roads to get to the hotel, electricity, sewers to handle waste, and water. All of these support facilities cost money. If they are not used because there are not enough tourists, jobs and money are lost. Which of the following has most probably been discussed in the paragraph that goes before the passage?
| A．It is extremely important to develop tourism. |
| B．Building roads and hotels is essential. |
| C．Support facilities are highly necessary. |
| D．Planning is of great importance to tourism. |
Too much tourism can cause all these problems EXCEPT.
| A．a bad impact on other industries |
| B．a change of tourists’ customs |
| C．over crowded of places of interest |
| D．pressure on traffic |
Not enough tourism can lead to.
| A．an increase of unemployment |
| B．a decrease in tourist attractions |
| C．the higher cost of support facilities |
| D．a rise in price and a fall in pay |
The word “handle” in the last paragraph most probably means.
| A．carry away | B．pick up | C．get in | D．take down |
About twenty of us had been fortunate enough to receive invitations to a film-studio（影棚）to take part in a crowd-scene. Although our "act" would last only for a short time, we could see quite a number of interesting things.
We all stood at the far end of the studio as workmen prepared the scene, setting up trees at the edge of a winding path. Very soon, bright lights were turned on and the big movie-camera was wheeled into position. The director shouted something to the camera operator and then went to speak to the two famous actors nearby. Since it was hot in the studio, it came as a surprise to us to see one of the actors put on a heavy overcoat and start walking along the path. A big fan began blowing tiny white feathers down on him, and soon the trees were covered in "snow". Two more fans were turned on, and a "strong wind" blew through the trees. The picture looked so real that it made us feel cold.
The next scene was a complete contrast (对比).The way it was filmed was quite unusual. Pictures taken on an island in the Pacific were shown on a glass screen. An actor and actress stood in front of the scene so that they looked as if they were at the water's edge on an island. By a simple trick like this, palm trees, sandy beaches, and blue, clear skies had been brought into the studio!
Since it was our turn next, we were left wondering what scene would be prepared for us. For a full three minutes in our lives we would be experiencing the excitement of being film “Stars”!Who is the author?
| A．A cameraman. | B．A film director. |
| C．A workman for scene setting | D．A crowd-scene actor |
What made the author feel cold?
| A．The heavy snowfall. | B．The film being shown. |
| C．The low temperature. | D．The man-made scene. |
What would happen in the "three minutes" mentioned, in the last paragraph?
| A．A new scene would be filmed. |
| B．More stars would act in the film. |
| C．The author would leave the studio. |
| D．The next scene would be prepared. |
One thing the tour books don’t tell you about London is that 2,000 of its residents are foxes. As native as the royal family, they fled the city about centuries ago after developers and pollution moved in. But now that the environment is cleaner, the foxes have come home, one of the many wild animals that have moved into urban areas around the world.
Several changes have brought wild animals to the cities. Foremost is that air and water quality in many cities has improved as a result of the 1970s pollution-control efforts. Meanwhile, rural areas have been built up, leaving many animals on the edges of suburbs. In addition, urban wildlife refuges (避难处) have been created. The Greater London Council last year spent $750, 000 to buy land and build 10 permanent wildlife refuges in the city. Over 1,000 volunteers have donated money and cleared rubble from abandoned spots. One evening last year a fox was seen on Westminster Bridge looking up at Big Ben.
For peregrine falcons (游隼), cities are actually safer than rural cliff dwellings (悬崖栖息地). By 1970 the birds had died out east of the Mississippi because the DDT had made their eggs too thin to support life. That year, scientist Tom Cade of Cornell University began raising the birds for release in cities, for cities afforded abundant food.
Cities can attract wild animals without turning them harmful. The trick is to create habitats where they can be self-sufficient but still be seen and appreciated. Such habitats can even be functional. In San Francisco, the local government is testing different kinds of rainwater control basins to see not only which ones retain (保持) the cleanest water but which will attract the most birds. The first paragraph suggests that ________.
| A．environment is the key to wildlife |
| B．tour books are not always a reliable source of information |
| C．London is a city of fox |
| D．foxes are highly adaptable to environment |
Which of the following is NOT a reason that wildlife is returning to the cities?
| A．Food is plentiful in the cities. |
| B．Wildlife is appreciated in the cities. |
| C．Wildlife refuges have been built in the cities. |
| D．Air and water quality has improved in the cities. |
It can be inferred from the passage that ________.
| A．Londoners are putting more and more wild animals into their zoos |
| B．Londoners are happy to see wild animals return to their city |
| C．Londoners are trying to move wild animals back to the countryside |
| D．Londoners have welcomed the wild birds, but found foxes a problem |
What is the passage mainly about?
| A．Wildlife returning to large cities. |
| B．Foxes returning to London. |
| C．Wild animals living in zoos. |
| D．A survey of wildlife in New York. |