Part 1
Tunnelling under the Thames
Tunnelling under the Thames
The first tunnel ever to be built under a major river was the tunnel under London’s River Thames.
At the beginning of the 19th century, the port of London was the busiest in the world. Cargoes that had travelled thousands of miles and survived all the hazards of the sea were unloaded on the banks of the Thames, only for their owners to discover that the most frustrating portion of their journey lay ahead. Consignments intended for the southern parts of Britain had to be lifted onto horse carts, pulled through the docks and across London Bridge, built in the 12th century and as impractical as its early date implies. By 1820, London Bridge had become the centre of the world’s largest traffic jam.
It was an intolerable situation, and it was clear that if private enterprise could build another crossing closer to the docks, there would be good money to be made in tolls paid by users. Another bridge was out of the question, as this would deny sailing ships access to the city centre, and ambitious men turned their thoughts to tunnelling beneath the Thames instead. This was not such an obvious idea as it might appear. Although increasing demand for coal had meant a great many tunnels had been dug in mines in Britain, working methods remained primitive. Tunnels were dug by men with simple tools, by candlelight. However, in 1807, a group of businessmen set themselves up as the Thames Archway Company. Their ambition was to tunnel below the Thames, but there was little to guide them, as there had been no previous attempt to do this. Their chief engineer was Richard Trevithick, designer of the world’s first high-pressure steam engine. His men made progress at the beginning, but then things began to go disastrously wrong, with muddy soil pouring into the tunnel. Eventually, the Thames Archway Company had had enough. Its funds were exhausted, Trevithick was sick from exposure to the river water, and its efforts had proved only that a passage under the river exceeded the limits of contemporary mining technology.
At that time, the only machines used in mines were pumps. It took a man of genius to recognise that a different sort of machine was needed, a machine that could prevent the roof and walls of a tunnel from collapsing. This man was Marc Brunel, a Frenchman who had become one of the most prominent engineers in Britain. Not long after the failure of the Thames Archway Company, Brunel saw a rotten piece of wood lying on the riverbank. Examining the wood through a magnifying glass, he observed that it was infested with something that looked like a worm. Brunel realised that as it tunnelled through the wood, it would push chewed wood into its mouth and digest it, then excrete a hard substance that lined the new tunnel. Brunel realised that the worm’s digging technique could be adapted to produce a new way of tunnelling.
His realisation led him to invent a device that has been used in one form or another in most major tunnels built since -- the tunnelling shield. It consisted of a heavy iron frame that could be pushed forward a few inches at a time. The front of the frame was made up of a series of iron frames that could be folded back to allow miners to dig the ground ahead. Behind these frames was a wall consisting of a series of iron plates pressed against the tunnel face and supported on a set of horizontal wooden planks, which would prevent the face from collapsing. It was a complex and rather cumbersome machine and not easy to use, but it seemed that it would protect the miners from the worst of the river’s water.
Brunel’s team carefully examined earth samples taken from beneath the riverbed and subsequently decided to dig the tunnel close to the muddy river bottom, where he could expect to find clay. This would be a more solid and safe substance to dig through than the sand that was found deeper down.
Brunel began work on his tunnel in 1825, but the problems of such an operation soon became apparent. Although the shield itself worked well, water began to drip into the tunnel. This was more of an annoyance than a danger while the pump was working, but this machine proved unreliable and sometimes failed altogether. When the pump broke down, work had to stop as the tunnel quickly flooded. There were occasions when the miners had to abandon their tools and flee for their lives. Even when Brunel’s men were able to work, they had to run the constant risk of the pumps failing.
They also complained of frequent headaches and dizziness, caused by the poor air quality. The air underground was dirty and stale, contaminated due to the lack of an adequate ventilation system. There were lighting problems too. Illuminating the tunnels by candlelight was a constant challenge. Lamps gave off only a very weak glow, and there were a number of accidents because the miners could not see what they were doing. Lastly, a number of Brunel’s miners walked off the job because they could not tolerate the excessive temperatures that developed in the cramped conditions underground.
Despite all these setbacks, the tunnel finally emerged on the opposite river bank on August 12, 1841. Brunel’s triumph, however, was only partial. The small payment per person made by the thousands of visitors who flocked to see the marvel hardly paid even a penny per foot of the tunnel’s construction costs. Brunel had gone bankrupt long before the project was completed, and the government loan he had required to complete the project had to be paid back with interest. As a result, there was not enough funding to make it accessible to horse-drawn vehicles, as intended. Instead, the passageways were filled with souvenir sellers and entertainers. In the end, the tunnel was closed two years later, used at night, before it was finally closed entirely and fell into dereliction for decades.
It was only when the underground railway came to London in the 1880s that the Thames Tunnel found and achieved a measure of real usefulness. It was bought in 1869 by the East London Railway, which found it to be in such excellent condition that it was immediately pressed into service as a route for passenger trains heading east. The tunnel became, and remains, part of the London Underground network.
Questions 1--8
Do the following statements agree with the information given in Reading Passage 1?
TRUE if the statement agrees with the information
FALSE if the statement contradicts the information
NOT GIVEN if there is no information on this
1. In the early 19th century, the port of London was considered a safer destination than other ports.
2. London Bridge provided quick access for cargo being sent to southern Britain.
3. It was generally believed that a new river crossing would be profitable.
4. Building a second bridge crossing was initially considered to be the best solution.
5. It was believed that coal could be found under the River Thames.
6. The Thames Archway Company was the first group to try tunnelling below the Thames.
7. Some of Trevithick’s men were injured when muddy soil entered the tunnel.
8. The Thames Archway Company ran out of money to finance the tunnel project.
Questions 9--13
Complete the notes below.
Choose ONE WORD ONLY from the passage for each answer.
Marc Brunel’s Tunnel
Preparing to build the tunnel
9. Brunel noticed how a kind of 9 made its tunnels in wood.
10. Brunel planned to build a shallow tunnel so that the earth would have a higher content of 10.
Problems faced by miners
11. The miners experienced frequent 11 and dizziness because of the poor air quality.
12. Lighting problems led to several 12.
After the tunnel was finished
13. The loan needed to complete the project came from the 13.
Part 2
Skyscraper Farming
Skyscraper Farming
With a global food crisis predicted, a group of scientists is advocating an innovative alternative to conventional farming that could radically transform the way food is produced.
Today’s environmental scientists are in no doubt that the world’s resources of fertile soil are rapidly deteriorating, and that new land for agriculture is becoming ever more scarce. Intensive farming, urbanisation, desertification and sea-level rises are all putting growing pressure on the planet’s agricultural land and therefore on food supplies. Currently, 24 per cent of the world’s 11.5 billion hectares of cultivated land has already undergone human-induced soil degradation, particularly through erosion, according to a recent study by the UK Government Office for Science.
The global population is expected to exceed nine billion by 2050 -- up a third from today’s level -- and studies suggest that food production will have to go up by 70 per cent if we are to feed all of those new mouths. This means that scientists will have to develop new ways of growing crops if we are to avoid a humanitarian crisis. Indeed, UN Food and Agriculture Organization figures suggest that the number of undernourished people is already growing. With escalating climate change, crop yields in many areas have been projected to decline.
With this in mind, some scientists and agricultural experts are advocating an innovative alternative to traditional farming whereby skyscrapers packed with shelf-based systems for growing vegetables on each storey -- known as "vertical farms" -- could hold the key to revolutionising agriculture. Columbia University professor Dickson Despommier claims that vertical farming could boost crop yields many times over. A single 20-storey vertical farm could theoretically feed 50,000 people, according to Despommier. If the theory translates into reality as proposed, 160 skyscraper-sized vertical farms could feed the entire population of New York City, while 180 would be needed to feed London, 289 to feed Cairo and 302 to feed Kolkata.
It is a compelling vision, and one that has already been put into practice in Asia, albeit on a smaller scale. However, there are problems, such as initial investment and operating costs that are "too great", says a spokesperson for Japan’s Ministry of Agriculture, Forestry and Fisheries. Nevertheless, Tokyo-based mushroom producer Hokuto Corporation is a model example of how a vertical farm can be profitable. With 28 vertical mushroom farms operating across the country, it produces some 68,000 tonnes of mushrooms annually. "Vertical mushroom farms have more advantages than ground-level farms," says Hokuto’s Ted Yamanoko. Yamanoko goes on to highlight the relative cost-effectiveness of his organisation’s farming practices, together with reduced emissions of greenhouse gases.
The impact of vertical farms could extend beyond feeding established urban populations. Despommier sees them as being capable of helping centres of displaced persons, such as refugee camps, in much the same way that Mobile Army Surgical Hospital units are deployed in emergency situations. "Developing an emergency-response system for crop production inside specially constructed modular and highly transportable greenhouses would allow for humanitarian interventions, at least for refugees who are forced out of their countries by political turmoil," he says. "If you have three or four storeys of food already growing somewhere, they could become mobile units that could be picked up by helicopters and dropped into the middle of a crisis zone. The food would be ready to pick and eat. It could be designed to supply people with all the nutrition they need to make it through the crisis."
However, it is not only about increasing food production. Despommier is concerned about the harm which farming has done to the world’s landscape over a relatively short time span, particularly the elimination of hardwood forests. "Farming is only 12,000 years old," he points out. "Vertical farming could allow us for the first time to feed everyone on earth and still return land to its original ecological function." Natalie Jeremijenko, associate professor at New York University, agrees. "The challenge that we have now is how we can design urban agriculture systems that not only reduce food miles, but also improve the world’s ecosystems," she says.
By significantly reducing the amount of land required for food production, vertical farms could help to enrich biodiversity. According to Jeremijenko, this can, in turn, help to improve the productivity of conventional farms, as the health of agricultural land is often tied to the health of the surrounding ecosystems. Furthermore, vertical farming could dramatically cut the utilisation of fossil fuels and reduce geopolitical tensions in countries where poor farming conditions cause conflict and malnutrition.
Questions 14--19
Choose the correct heading for each paragraph from the list of headings below.
Drag the correct heading and drop it into the appropriate space in the passage.
* Drag a heading and drop it into the blank space.
Questions 20--22
Complete the sentences below.
Choose NO MORE THAN TWO WORDS from the passage for each answer.
20. A UK Government study found that 20 is a significant factor contributing to worldwide levels of soil degradation.
21. Disadvantages of vertical farming projects include the expense of setting them up, as well as their high 21.
22. 22 could potentially be used to take vertical farming facilities to areas where there is a critical food shortage.
Questions 23--26
Look at the following statements and the list of people below.
Match each statement with the correct person, A--C.
NB You may use any letter more than once.
23. Vertical farming can have financial benefits.
23
24. Traditional farming has had a negative effect on the natural world.
24
25. Vertical farming could dramatically increase world food production.
25
26. Traditional farms may benefit from wider use of vertical farming.
26
Part 3
The Hazards of Multitasking
The Hazards of Multitasking
Doing more than one thing at once -- is it always a good idea?
You arrive at the office, review your to-do list and start to feel a headache coming on. You resolve to tackle the items as quickly as possible. While you return calls, you sort email and other letters. You begin keying in slides for tomorrow’s presentation. Then your manager comes in wanting an immediate update on sales figures. You have just opened the spreadsheet when a very important customer calls. With the receiver held between your shoulder and your ear, you continue adding up the sales totals until, 15 minutes later, you finally manage, politely, to get rid of the client. You have been multitasking again.
You may believe that anyone who wants to get ahead today should master the art of multitasking. However, a recent study by the Families and Work Institute in New York City has found that 45 per cent of US workers believe that they are asked or expected to work on too many tasks at once. Managers may be surprised to learn that they are actually wasting their workers’ time. As it turns out, the human brain cannot really master the computer’s art of crunching data in the background while moving between process windows.
Instead, a growing number of studies show that trying to juggle jobs rather than completing them sequentially can take longer and leave workers with a reduced ability to perform each task. In addition, the stress associated with multitasking may contribute to short-term memory difficulties. The combination results in inefficiency, careless thinking and mistakes -- not to mention the possible dangers of divided attention for drivers, air traffic controllers and others who handle machinery.
How can a time-management strategy that has become part of the common wisdom actually be so wrong? Exploring that question requires a closer look at an area of consciousness research that examines how the brain focuses attention. One of the modern foundations of current knowledge of multitasking was laid in 1935, when the American psychologist John Ridley Stroop reported that processing information from one task could cause interference with another.
Stroop noticed that when study participants were asked to name the colour of a word -- such as "green" -- printed in a different colour, red, for example, they experienced difficulty saying the name of the colour. This phenomenon is thought to occur when two tasks get tangled: the brain must suppress one that has been learned so well that it has become automatic, reading, in order to attend to a second task that requires concentration, naming the colour.
During the past couple of decades, psychologists have probed more deeply into the nature and limitations of multitasking. Psychologist and brain researcher Ernst Pöppel, of Ludwig Maximilian University in Munich, believes that it is impossible to carry out two or three different tasks simultaneously with the same degree of concentration. He says that seemingly simultaneous awareness and processing of information actually takes place in "three-second windows".
In these three-second segments, the brain takes in, as a block, all the data about the environment streaming in from the sensory systems; subsequent events are processed in the next window. Therefore, a person can concentrate on a conversation for three seconds, then for three seconds on a crying child, and for three seconds on a computer screen. While one subject at a time occupies the foreground of consciousness, the others stay in the background until they, in turn, are given access to the central processor.
Another experiment by psychologist David E Meyer, of the University of Michigan, quantified just how much time we can lose when we shuttle between tasks. The researchers asked test participants to write a report and check their email at the same time. Those individuals who constantly jumped back and forth between the two tasks took about one and a half times as long to finish as those who completed one job before turning to the other. Each switchover from one task to another meant rethinking and thus involved additional neural resources.
In effect, the brain needs time to shut off the rules for one task and to turn on the rules for another. "Multitasking saves time only when it is a matter of relaxed, routine tasks," Meyer says. It also takes the brain longer to adapt when switching rapidly back to an interrupted task, rather than waiting longer before switching back.
By its nature, multitasking is stressful, and the area in the brain most involved with multitasking is also most affected by the resulting stress. Located behind the forehead, the prefrontal cortex, which neuroscientists call the "executive" part of the brain, helps us to assess tasks, prioritise them and assign mental resources. It also "marks" the spot at which a task has been interrupted, so that we can return to it later.
This stress can also affect brain cells in another region, the hippocampus, which is important for forming new memories. Damage in that area also makes it difficult for a person to acquire new skills.
Psychiatrists Edward Halliwell and John Ratey, of Harvard University, say that multitasking can bring about a brain condition that causes sufferers to constantly seek new information while having difficulties concentrating on its content. All in all, it may be wise to let the email wait while you work on your presentation. You will save time and perform each task better.
Questions 27--31
Look at the following theories and the list of people below.
Match each theory with the correct person or people, A--D.
NB You may use any letter more than once.
27. Less attention will be paid to each task when more than one task is attempted at the same time.
27
28. Repeated changes of task mean that the brain will take a while to adjust.
28
29. Using the skills required for one task may make performing another one more difficult.
29
30. When multitasking, the brain can only focus on individual tasks for very short periods.
30
31. Multitasking can lead to a medical condition.
31
Questions 32--34
Choose the correct letter, A, B, C or D.
32. What is suggested about the worker in the opening paragraph?
33. Drivers and air traffic controllers are mentioned in the passage because they
34. In John Ridley Stroop’s experiment, participants found it difficult to
Questions 35--39
Complete the summary below.
Choose NO MORE THAN TWO WORDS from the passage for each answer.
Multitasking and Its Effects on the Brain
The stressful nature of multitasking has been shown to affect parts of the brain. The area most affected is the prefrontal cortex, which is found behind the 35. It is the part of the brain which assesses tasks, puts them in order of importance and allocates 36. It also enables a worker to resume a task which has been interrupted.
A second area, the hippocampus, may also be affected by the stress of multitasking. If 37 in the hippocampus are damaged, people may have problems forming 38, as well as acquiring 39.
Question 40
Choose the correct letter, A, B, C or D.
40. The main aim of this passage is to
