READING PASSAGE 1

You should spend about 20 minutes on Questions 1-13 which are based on Reading Passage 1 below.

The Mysteries of Water

Section A

From the nature of dark matter and the origin of the universe to the research for a theory of everything, we come across many mysteries. Whilst these are all puzzles on a grand scale, there is another not quite so grand but equally confusing mystery of the physical world that you can observe from the comfort of your own kitchen. Simply fill a tall glass with chilled water, throw in an ice cube and leave it to stand. The fact that the ice cube floats is the first oddity. And the mystery deepens if you take a thermometer and measure the temperature of the water at various depths. At the top, near the ice cube, you’ll find it to be around 0^oC, but at the bottom, it should be about 4^oC. that’s why water is denser at 4^oC than it is at any other temperature which is another strange feature that sets it apart from other liquids.

Section B

Water’s odd but essential qualities don’t stop there, for ice is less dense than water, and water is less dense at its freezing point than it is when it is slightly warmer. It freezes from the top down rather than the bottom up. So even during the ice ages, life kept going on to flourish on lake floors and in the deep ocean. Also, water has an extraordinary capacity to absorb up the heat, and this helps smooth out climatic changes that could otherwise lay waste to ecosystems. However, in spite of water’s enormous importance to life, no single theory had been able to satisfactorily explain its mysterious qualities – until now. If we can believe physicists Anders Nilsson at Stanford University, California, and Lars Pettersson of Stockholm University, Sweden, we could, at last, be getting to the bottom of many of these anomalies.

Section C

Their disputed ideas expand on a theory proposed more than a century ago. According to Wilhelm Roentgen, the man who discovered the X-ray, the molecule in liquid water packs together not in just one way, as today’s textbooks would have us believe, but in two different ways. The way its molecules are composed of two hydrogen atoms and one oxygen atom and how they interact with one another is essential to the understanding of water’s mysteries. The oxygen atom has a slight negative charge whilst the hydrogen atoms share a compensating positive charge. Through this process, the hydrogen and oxygen atoms of neighbouring molecules are drawn to one another, forming a link called a hydrogen bond.

Section D

Hydrogen bonds are even weaker than the bonds that link the atoms within molecules together, so keep going to break and reform, but they are at their strongest when molecules are organized so that each hydrogen bond lines up with a molecular bond. The shaping of a water molecule is such that each H20 molecule is surrounded by four neighbours organized in the shaping of a triangular pyramid better known as a tetrahedron. At least, that’s the way the molecules organize themselves in ice. From the conventional view, liquid water has a similar, although less hard, structure, in which extra molecules are able to pack into some of the open gaps in the tetrahedral arrangement. It explains why liquid water is denser than ice – and it seems to comply with the results of various experiments that beams of X-rays, infrared light and neutrons are bounced off samples of water.

Section E

Some physicists had suggested that water placed under certain extreme conditions may separate into two different structures, but most had assumed it resumes a single structure under normal conditions. And then, 10 years ago, a change found by Pettersson and Nilsson called this idea into question. They were using X-ray absorption spectroscopy to research the amino acid glycine. The peaks in the X-ray absorption spectrum can shed light on the accurate nature of the target substance’s chemical bonds on its structure. Critically, the researchers had got hold of a new, high-power X-ray source with which they could make more sensitive and precise measurements than had ever been possible. They soon knew that the water containing their glycine sample was producing a far more interesting spectrum than the amino acids did. Nilsson recalls, “What we saw there was sensational, so we had to get to the bottom of it.”

Section F

The characteristic that sparked their interest was a peak point in the absorption spectrum that is not anticipated by the traditional model of liquid water. Actually, a paper published in 2004 concludes that at any given moment 85% of the hydrogen bonds in water must be weakened or broken. This is far more than the 10% anticipated by the textbook model. The hints of this finding are dramatic: it claims that a total rethink of the structure of water is needed. So, both Nilsson and Pettersson turned to other X-ray experiments to confirm these claims. Their first move was to enlist the aid of Shik Shin of the University of Tokyo who specialises in a technique called X-ray emission spectroscopy. The main thing about these spectra is that the shorter the wavelength of the X-ray in a substance’s emission spectrum is, the looser the hydrogen bonding must be.

The team struck gold: the two peak spectrum of discharged X-ray might correspond to two separate structures. The researchers insisted that the spike of the longer-wavelength X-ray indicates the proportion of tetrahedrally organized molecules, whilst the shorter-wavelength peak reflects the proportion of disordered molecules. Critically, the shorter-wavelength peak in the X-ray emissions was the more intense of the two, suggesting that the loosely bound molecules must be more outstanding within the sample, an assertion that fitted the team’s previous models. What’s more, they also recognised that this peak shifts to an even shorter wavelength, as if the water was heated, the other peak remains more or less fixed.

Questions 1-5

Reading Passage 1 has six sections, A-F.

Choose the correct heading for sections B-F from the list of headings below.

Write the correct number, i-viii, in boxes 1-5 on your answer sheet.

List of Headings

i           a significant role to creatures

ii          spectrum’s previous models

iii         a distinction of hydrogen bonds

iv         nature’s mysteries in the small place

v          the effect of the spectrum on liquid water

vi         molecular composition of water

vii        water based on infrared light

viii       on-body structure of water

            Example          Answer

            Section A         iv

1   Section B

2   Section C

3   Section D

4   Section E

5   Section F

Questions 6-13

Do the following statements reflect the claims of the writer in Reading Passage 1?

In boxes 6-13 on your answer sheet, write

YES                  if the statement reflects the opinion of the writer

NO                   if the statement contradicts the opinion of the writer

NOT GIVEN    if it is impossible to say what the writer thinks about this

6   Water’s temperature of the top and bottom is generally the same.

7   During the ice ages, there was life in the deep ocean because of warmth.

8   Wilhelm Roentgen discovered X-rays for water molecules.

9   Both hydrogen and oxygen’s atoms are similar to a positive charge.

10   A single H20 molecule is composed entirely of five-angled shape.

11   Pettersson and Nilsson were scrutinising the amino acid glycine by using X-ray absorption spectroscopy.

12   The water including glycine was making a superior spectrum to the amino acid.

13   The shorter wavelength is subjected to the longer wavelength.

READING PASSAGE 2

You should spend about 20 minutes on Questions 14-28 which are based on Reading Passage 2 below. 

Vehicle Safety Systems

Although drivers and their passengers are encased in the event of a crash, people hit by a car have no protection. Now that could change thanks to a new system built into a vehicle that will enhance a pedestrian’s safety. Every month about 3,400 pedestrians are killed in traffic accidents of the roads in the US, and a similar number die in Europe. Some 30% of the injuries included in this group are caused by an impact with a windscreen or its frame.

A European-wide collaboration led by Roger Hardy of the Cranfield Impact Centre at Cranfield University close to Bedford in the UK has devised an experimental system for cars that aims to cut this death toll and decrease the risk of injuries. When the system registers that the car is about to hit a pedestrian, it automatically raises the rear of the bonnet (hood), releasing a giant airbag in front of the windscreen.

“The raised bonnet absorbs some of the energy of the impact, decreasing the risk of severe injury to the pedestrian,” says Hardy, whose project forms part of the European Union-funded Integrated Project on Advanced Protection Systems (APROSYS). “If it’s a large pedestrian or on a small town car, the airbag also offers a cushioning effect around the stiff peripheral regions of the windscreen,” he says. The airbag system used by Hardy was enhanced by the German company Takata Petri. To test its efficacy when combined with the raised bonnet, they cooperated into developing a prototype Fiat Stilo by engineers at the Fiat Research Centre in Turin, Italy. Then the team estimated the danger of head injuries in test collisions with a dummy pedestrian.

A standard Stilo test hitting a pedestrian at 40 kilometres per hour would have a score of around 1,000 on the Head Impact Criterion (HIC) scale. That is the equivalent of an 18% chance of a life-threatening injury. For pedestrians hitting Hardy’s bonnet, the scores were reduced to between 234 and 682, whilst the normal windscreen airbag scores ranged between 692 and 945. Hardy’s team has also introduced a design in which a windscreen mounting system cushions the impact with the edge of the windscreen. This consists of a flexible Z-shaped section of metal, that is a maximum of 15 millimetres wide, separating the windscreen from its frame so that it is able to flex inwards to absorb energy in a collision. The team says it could decrease HIC scores by over 50%.

Another APROSYS collaboration led by Jurgen Gugler at the Graz University of Technology in Austria researched how changing the shaping of the front of a truck could reduce the risk to pedestrians. Computer simulations of 20 accident scenarios indicated that a smooth sloping surface with a central bulge decreases the likelihood of a pedestrian involved in a front-end accident being run over by 80 to 90%. Gugler says, “The pedestrian is knocked to the side, rotated and pushed towards the ground. You are out of the path of the oncoming truck.”

Fiat researchers managed by Roberto Puppini have also had some success in early tests of an adaptive bumper system. Four gas springs kick in at high speeds to move the bumper forward so that it will absorb the energy of an impact. So will manufacturers actually incorporate any of these safety innovations into their cars? Over the next two years, the European New Car Assessment Programme (Euro NCAP) will be phasing the results of pedestrian safety tests into its essential rating system. Poor Euro NCAP test results could result in less safe car models being withdrawn from the market. This suggests that buyers and manufacturers can be persuaded to take the safety of drivers and their passengers seriously, buy it remains to be seen whether the welfare of pedestrians is as persuasive a selling point.

For now, at least, there is little else to convince car manufacturers to install these safety devices. Hardy says, “Recently, from the legislative point of view, there is not a colossal incentive for manufacturers to utilise these technologies.” Perhaps ultimately the law will have to step in so that external airbags and energy-absorbing bodywork enhance pedestrian safety as dramatically as seat belts and internal airbags have enhanced driver and passenger safety.

Questions 14-20

Complete the summary below.

Choose NO MORE THAN THREE WORDS from the passage for each answer.

Write your answers in boxes 14-20 on your answer sheet.

Every month there are about 3,400 people hit by a car in the US and a similar number of casualties in 14……………………… Actually, around 30% of them are a result of 15……………………… or its frame. To decrease road traffic accidents, a European-wide collaboration devised automatic lifting rear of 16………………………., and a 17…………………………. Ahead of the windscreen working at the same time.

Hardy’s team has researched a system to cushion impacts with the outline of 18……………………….. It includes an easily bent and 19……………………….. metal frame with the windscreen and frame separated. But he said: According to law, although having safety devices for protection against a crash, now any manufacture companies to harness these devises could not have 20………………………

Questions 21-25

Complete each sentence with the correct ending, A-G, below.

Write the correct letter, A-G, in boxes 21-25 on your answer sheet.

21   A European-wide collaboration

22   European Union-funded Integrated Project

23   APROSYS collaboration

24   Euro NCAP

25   Poor Euro NCAP

A     be part of schemes to decrease hazardous situations for pedestrians.

B     help judge less safe vehicle models between buyers and companies.

C     improve testing under the condition that a crash decreased.

D     make a solution within the frequency of tests for safe pedestrians.

E     study how replacing a lorry’s front side protects pedestrians.

F     be persuasive as a selling point.

G    improve a pedestrian’s chances.

Questions 26-28

Choose the correct letter, A, B, C or D.

Write the correct letter in boxes 26-28 on your answer sheet.

26   Which one of the following is found in the passage?

A   the number of traffic accidents and rubbish on the road

B   the amount of petrol gas misused and recycled

C   the number of casualties in traffic accidents on the road

D   the cases of car insurance in a court

27   What are the main technical devices made by Roger Hardy?

A   brake system

B   automatic both bonnet and airbag system

C   instant front door and trunk open

D   anti-slip tires during heavy rain and snow

28   The writer believed that the “Hardy’s team” on the system could

A   decrease in the Head Impact Criterion (HIC) score until over half per cent.

B   be almost as safe as computer simulation tests.

C   be causing significant damage to half per cent of the Head Impact Criterion (HIC).

D   reduce converting the windscreen airbag.