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. |
When I was going home to India last year, I called up my mother to ask if she wanted anything from China．
When India had not opened up its markets to the world, I carried suitcase loads of dark glasses and jeans．Thankfully, we can get all these anywhere in India now．
Still, her answer surprised me: “Green tea．”
As long as I can remember she didn’t even drink Indian tea ．
I dutifully bought a big packet of Longjing and headed home to hear the story．My mother and her brother, both regular newspaper readers, believed that Chinese green tea was the wonder drug for all illnesses．
At the turn of the century, China was not really familiar to the average Indian．It was a strange country．
How things change! And how soon!
Now every town of any size seems to have a “China Market”．And everyone is talking about China．
The govemment of Indin has planned to send a team to China to see how things are done．A minister once said that India must open the doors for more foreign investment(投资)and such a step would “work wonders as it did for China”．
But it’s a two-way street．I just heard about a thousand Shenzhen office workers who have gone to Bangalore to train in software．Meanwhile, all the Indian IT majors are setting up a strong presence in China．
No wonder that trade, which was only in the millions just ten years ago, is expected to hit about US $15 billion for last year and US $20 billion by 2008, a goal set by both governments．
No wonder, my colleague wrote some weeks ago about this being the Sino-Indian(中印)century as the two countries started on January 1 the Sino-Indian Friendship Year．
But what is still a wonder to me is my mother drinking Chinese tea．According to the passage, the author left _____ for ______．
| A．India; China | B．China; India |
| C．China; Longjing | D．India; Shenzhen |
The reason why the writer’s mother asked for Chinese green tea is that_____．
| A．she had a son working in China | B．she believed it had a curing effect |
| C．she enjoyed Chinese products | D．she was tired of Indian tea |
The underlined part “it’s a two-way street” in Paragraph 10 probably means ____．
| A．The exchanges between Indian and China benefit both． |
| B．China and India have different traffic rules． |
| C．Tea trade works wonders in both India and China． |
| D．Chinese produces are popular in both China and India． |
It can be inferred from the passage that _______．
| A．the author was concerned for his mother’s health |
| B．the author was in favor of drinking Chinese green tea |
| C．the author was surprised at China’s recent development |
| D．the author was curious about the growth of India’s IT industry |
All too often , a choice that seems sustainable（可持续的）turns out on closer examination to be problematic. Probably the best example is the rush to produce ethanol（乙醇）for fuel from corn . Corn is a renewable resource —you can harvest it and grow more, almost limitlessly. So replacing gas with corn ethanol seems like a great idea.
One might get a bit more energy out of the ethanol than that used to make it, which could still make ethanol more sustainable than gas generally, but that’s not the end of the problem. Using corn to make ethanol means less corn is left to feed animals and people, which drives up the cost of food. That result leads to turning the fallow land — including, in some cases, rain forest in places such as Brazil — into farmland, which in turn gives off lots of carbon dioxide（CO2）into the air. Finally, over many years, the energy benefit from burning ethanol would make up for the forest loss. But by then, climate change would have progressed so far that it might not help.
You cannot really declare any practice “sustainable” until you have done a complete lift-cycle analysis of its environmental（环境的）costs. Even then, technology and public policy keep developing, and that development can lead to unforeseen and undesired results. The admirable goal of living sustainable requires plenty of thought on an ongoing basis.What might directly cause the loss of the forest according to the text?
| A．The growing demand for energy to make ethanol. |
| B．The increasing carbon dioxide in the air. |
| C．The greater need for farmland. |
| D．The big change in weather. |
The underline word “it” in the second paragraph refers to
| A．the energy benefit | B．the forest loss |
| C．climate change | D．burning ethanol |
The author thinks that replacing gas with corn ethanol is
| A．impractical | B．acceptable | C．admirable | D．useless |
What does the author mainly discuss in the text?
| A．Technology. | B．Sustainability. |
| C．Ethanol energy. | D．Environmental protection. |
Cities alarmed by deaths and injuries of pedestrians are taking efforts to make crosswalks safer for people on foot, especially seniors and children who need more time to cross streets.
A pedestrian is killed in a traffic accident in the USA every 110 minutes；one is injured every nine minutes, according to official date. Crosswalk can be especially dangerous for the elderly. Among people 70 and older, 36% of pedestrian deaths in 2006 occurred in crosswalks, compared with 21% of those younger than 70, according to the Insurance Institute for Highway Safety.
The Federal Highway Administration（FHWA）advises that next year states increase by nearly 15% the amount of time traffic lights provide for pedestrians to cross the street after the flashing orange hand appears .
FHWA spokesman Doug Hecox says reasons for the change include an aging population that needs more time to cross, health-conscious Americans walking more, children encouraged to walk to prevent getting overweight and high gas prices pushing people to walk instead of drive.
Pedestrian deaths went down by 12% from 5,449 in 1996 to 4,784 in 2006. But among those in 2006, 471 were killed in crosswalks, down slightly from 488 ten years earlier, the National Highway Traffic Safety Administration (NHTSA) says.Which of the following is true according to the text?
| A．Among 100 pedestrian deaths there were 21 people younger than 70. |
| B．Old people are more likely to meet with accidents in crosswalks. |
| C．Traffic accidents killed more old people than young people. |
| D．About seven traffic accidents happened per hour. |
What is FHWA’s suggestion to states?
| A．Fixing more traffic lights. |
| B．Providing more crosswalks. |
| C．Giving pedestrians more time to cross streets. |
| D．Increasing the time before the orange lights appear. |
What’s the cause of the crosswalk safety problem according to the test?
| A．There’re many cars and buses on the road. |
| B．Pedestrians are careless. |
| C．Crosswalks are crowded. |
| D．Drivers don’t give way. |
The report from NHTSA suggests that
| A．fewer people were injured in crosswalks |
| B．crosswalk safety has been greatly improved |
| C．much has been done to reduce traffic accidents |
| D．pedestrian deaths in crosswalk remain a serious problem |
Honesty comes in many forms. First there’s self-honesty. Is what people see the real article or do you appear through smoke and mirrors? I find that if I try to be something I’m not , I feel unsure of myself and take out a part from my PBA(personal bank account ).I love how singer Judy Garland put it, “Always be a first-class version(版本) of yourself , instead of a second-class version of somebody else .”
Then there’s honesty in our actions. Are you honest at school, with your parents, and with your boss? If you’ve ever been dishonest, I think we all have, try being honest, and notice how whole it makes you feel. Remember, you can’t do wrong and feel right. This story by Jeff is a good example of that:
In my second year of study, there were three kids in my math class who didn’t do well. I was really good at it. I would charge them three dollars for each test that I helped them pass. I’d write on a little piece of paper all the right answers, and hand them off.
At first I felt like I was making money, kind of a nice job. I wasn’t thinking about how it could hurt all of us. After a while I realized I shouldn’t do that anymore, because I wasn’t really helping them. They weren’t learning anything, and it would only get harder down the road. Cheating certainly wasn’t helping me.
It takes courage to be honest when people all around you are getting away with cheating on tests, lying to their parents, and stealing at work. But, remember, every act of honesty is a deposit（储蓄）into your PBA and will build strength.The underlined part “appear through smoke and mirrors” in the first paragraph means “”.
Which of the following can best explain Judy Garland’s words?
| A．Be your true self rather than follow others. |
| B．Don’t copy others or you can’t be the first class. |
| C．Make efforts to be the first instead of the second. |
| D．Don’t learn from others unless they’re excellent. |
What does the author expect to show by Jeff’s story ？
| A．honesty can be of great help. |
| B．A bad thing can be turned into a good one. |
| C．Helping others cheat can do good to nobody. |
| D．One should realize the wrong in his bad deeds. |
In the last paragraph the author mainly wants to express .
| A．one must be brave to be honest |
| B．it’s difficult to be honest when others are not |
| C．one should be honest when making a deposit |
| D．honesty in one’s actions can help him in the future |
July 21st, 2007 was a typical English summer’s day — it rained for 24 hours! As usual, I rushed home from work at midday to check on the house. Nothing was amiss. By the time I lift work at 5 pm, however, the road into our village was flooded. Our house bad never been flooded but, as I opened the front door, a wave of water greeted me. Thank God the kids weren’t with me, because the house was 5 feet deep in water. We lost everything downstairs. And the plaster had to be torn off the walls, ceilings pulled down.
At first we tried to push on through. We didn’t want to move the children out of home, so we camped upstairs. we put a sheet of plastic across the floor to protect us from the damp. But after three months, we felt very sick, so we moved to a wooden house in a park. The house was small, but at first we were all just delighted to be in a new place. Unfortunately, things took longer than expected and we were there for 10 months. The life there was inconvenient. What surprised me most was how much I missed being part of a community（社区）.We had lived in a friendly village with good neighbours, and I’d never thought how much I’d miss that.
Although-our situation was very bad, it’s difficult to feel too sorry for yourself when you look at what’s happening elsewhere. I watched a news report about floods in Northern India and thought , “We didn’t have a straw hut（茅草房）that was swept away , and our house is still sanding . We’re lucky .”
We moved back home in August. With December coming, there’s reconstruction work to be done, so it’s difficult to prepare for Christmas. But I can’t wait — I’m going to throw a party for our friends in the village to say thanks for their support. This year , I won’t need any gifts — living away from home for months has made me realize how little we actually need or miss all our possessions . Although we are replacing things, there’s really no rush — we have our home back, and that’s the main thing.What does the underlined word “amiss” in the first paragraph mean?
| A．Wrong. | B．Missing. | C．Right. | D．Found. |
It can be inferred from the text that the author .
| A．was sick of staying upstairs |
| B．cared much about her children |
| C．could not stand living a wooden house |
| D．did not deal well with her family affairs during the flood |
Why does author say that they were lucky in the third paragraph?
| A．Because her situation was not serious. |
| B．Because many other places were flooded. |
| C．Because she had been to Northern India. |
| D．Because some others suffered even more. |
What does the author mainly want to express by telling her story?
| A．She valued human feelings more than before. |
| B．She realized she almost didn’t need possessions. |
| C．She found Christmas gifts no longer badly needed. |
| D．She thought her own home was the most important. |