Sentence Completion and Note Completion

Chimpanzees and humans share a common ancestor. Analysis of the teeth of these common ancestors provides strong evidence that they had a variable diet of both plant and animal foods. The plant foods would have included fruits, seeds, grasses and roots, while animal foods would have included worms, insects, and possibly some found or hunted meats. It is important to understand that, although the common ancestors of ourselves and chimpanzees lived several million years ago, they must have been very well adapted to their environment, otherwise they would have quickly become extinct. In addition, because we know our more recent ancestors hunted meat, and because chimpanzees do hunt meat on occasion, it is reasonable to suppose that our common ancestors behaved in the same way.

Two key changes took place when our human ancestors first moved away from the chimpanzees: how they foraged for food, and what they ate. Significant changes in the climate at that time would have affected the whole environment and landscapes, causing our ancestors to adapt their diet so they could exist more efficiently in their new surroundings. A result of this may have been the division of work between male and female, the young and the old. From what we know about modern hunter-gatherers, as well as chimpanzees, it is the males that form the hunting parties. This leaves the females and the young to remain at, or near the home base. So until very recently, the males would have spent their days hunting, while the females, the children and the elderly participated in food gathering and food preparation. Roots, for example, needed digging, and usually had to be crushed, soaked and cooked to remove poisons and improve their quality.

The marriage of Pierre and Marie Curie in 1895 marked the start of a partnership that was soon to achieve results of world significance. Following Henri Becquerel's discovery in 1896 of a new phenomenon, which Marie later called radioactivity, Marie Curie decided to find out if the radioactivity discovered in uranium was to be found in other elements. She discovered that this was true for thorium. Turning her attention to minerals, she found her interest drawn to pitchblende, a mineral whose radioactivity, superior to that of pure uranium, could be explained only by the presence in the ore of small quantities of an unknown substance of very high activity. Pierre Curie joined her in the work that she had undertaken to resolve this problem, and that led to the discovery of the new elements, polonium and radium.

While Pierre Curie devoted himself chiefly to the physical study of the new radiations, Marie Curie struggled to obtain pure radium in the metallic state. This was achieved with the help of the chemist Andre-Louis Debierne, one of Pierre Curie's pupils. Based on the results of this research, Marie Curie received her Doctorate of Science, and in 1903 Marie and Pierre shared with Becquerel the Nobel Prize for Physics for the discovery of radioactivity.

The births of Marie's two daughters, Irene and Eve, in 1897 and 1904 failed to interrupt her scientific work. She was appointed lecturer in physics at the Ecole Normale Superieure for girls in Sevres, France, and introduced a method of teaching based on experimental demonstrations. In December 1904 she was appointed chief assistant in the laboratory directed by Pierre Curie.

The sudden death of her husband in 1906 was a bitter blow to Marie Curie, but was also a turning point in her career. Henceforth she was to devote all her energy to completing alone the scientific work that they had undertaken. On May 13, 1906, she was appointed to the professorship that had been left vacant on her husband's death, becoming the first woman to teach at the Sorbonne. In 1911 she was awarded the Nobel Prize for Chemistry for the isolation of a pure form of radium.

During World War I, Marie Curie, with the help of her daughter Irene, devoted herself to the development of the use of X-radiography, including the mobile units which came to be known as Little Curies, used for the treatment of wounded soldiers. In 1918 the Radium Institute, whose staff Irene had joined, began to operate in earnest, and became a centre for nuclear physics and chemistry.

In 1921, accompanied by her two daughters, Marie Curie made a triumphant journey to the United States to raise funds for research on radium. Women there presented her with a gram of radium for her campaign. Marie also gave lectures in Belgium, Brazil, Spain and Czechoslovakia and had the satisfaction of seeing the development of the Curie Foundation in Paris and the inauguration in 1932 in Warsaw of the Radium Institute, where her sister Bronia became director.

One of Marie Curie's outstanding achievements was to have understood the need to accumulate intense radioactive sources, not only to treat illness but also to maintain an abundant supply for research. The existence in Paris at the Radium Institute of a stock of 1.5 grams of radium made a decisive contribution to the success of the experiments undertaken in the years around 1930. This work prepared the way for the discovery of the neutron by Sir James Chadwick and, above all, for the discovery in 1934 by Irene and Frederic Joliot-Curie of artificial radioactivity. A few months after this discovery, Marie Curie died as a result of leukaemia caused by exposure to radiation.

Her contribution to physics had been immense, not only in her own work, the importance of which had been demonstrated by her two Nobel Prizes, but because of her influence on subsequent generations of nuclear physicists and chemists.

Brick by brick, six-year-old Alice is building a magical kingdom. Imagining fairy-tale turrets and fire-breathing dragons, wicked witches and gallant heroes, she is creating an enchanting world. Although she is not aware of it, this fantasy is helping her take her first steps towards her capacity for creativity and so it will have important repercussions in her adult life.

Minutes later, Alice has abandoned the kingdom in favour of playing schools with her younger brother. When she bosses him around as his teacher, she is practising how to regulate her emotions through pretence. Later on, when they tire of this and settle down with a board game, she is learning about the need to follow rules and take turns with a partner.

Play in all its rich variety is one of the highest achievements of the human species, says Dr David Whitebread from the Faculty of Education at the University of Cambridge. It underpins how we develop as intellectual, problem-solving adults and is crucial to our success as a highly adaptable species.

Recognising the importance of play is not new: over two millennia ago, the Greek philosopher Plato extolled its virtues as a means of developing skills for adult life, and ideas about play-based learning have been developing since the 19th century.

But we live in changing times, and Whitebread is mindful of a worldwide decline in play, pointing out that over half the people in the world now live in cities. The opportunities for free play are becoming increasingly scarce. Outdoor play is curtailed by perceptions of risk to do with traffic, parents' increased wish to protect their children from being the victims of crime, and by the emphasis on earlier is better, which is leading to greater competition in academic learning and schools.

International bodies like the United Nations and the European Union have begun to develop policies concerned with children's right to play and to consider implications for leisure facilities and educational programmes. But what they often lack is the evidence to base policies on.

The type of play we are interested in is child-initiated, spontaneous and unpredictable, explains Dr Sara Baker. We want to know what the long-term impact of play is. It is a real challenge.

Dr Jenny Gibson agrees, pointing out that although some of the steps in the puzzle of how and why play is important have been looked at, there is very little data on the impact it has on the child's later life.

Now, thanks to the university's new Centre for Research on Play in Education, Development and Learning, Whitebread, Baker, Gibson and a team of researchers hope to provide evidence on the role played by play in how a child develops.

A strong possibility is that play supports the early development of children's self-control. This is the ability to develop awareness of our own thinking processes and it influences how effectively we go about undertaking challenging activities.

If playful experiences do facilitate this aspect of development, it could be extremely significant for educational practices, because the ability to self-regulate has been shown to be a key predictor of academic performance.

Gibson adds that playful behaviour is also an important indicator of healthy social and emotional development. Observing children at play can give important clues about their well-being and can even be useful in the diagnosis of neurodevelopmental disorders like autism.

Whitebread's recent research has involved developing a play-based approach to supporting children's writing. Children wrote longer and better-structured stories when they first played with dolls representing characters in the story. In the latest study, children first created their story with Lego, with similar results.

Somehow the importance of play has been lost in recent decades. It is regarded as something trivial, or even as something negative that contrasts with work. Let us not lose sight of its benefits and the fundamental contributions it makes to human achievements in the arts, sciences and technology.

No treatment on the market today has been proved to slow human aging. But one intervention, consumption of a low-calorie yet nutritionally balanced diet, works incredibly well in a broad range of animals, increasing longevity and prolonging good health. Those findings suggest that caloric restriction could delay aging and increase longevity in humans, too. But what if someone could create a pill that mimicked the physiological effects of eating less without actually forcing people to eat less, a caloric-restriction mimetic?

The best-studied candidate for a caloric-restriction mimetic, 2DG, works by interfering with the way cells process glucose. It has proved toxic at some doses in animals and so cannot be used in humans. But it has demonstrated that chemicals can replicate the effects of caloric restriction; the trick is finding the right one.

Cells use the glucose from food to generate ATP, the molecule that powers many activities in the body. By limiting food intake, caloric restriction minimizes the amount of glucose entering cells and decreases ATP generation. When 2DG is administered to animals that eat normally, glucose reaches cells in abundance but the drug prevents most of it from being processed and thus reduces ATP synthesis.

Researchers have proposed several explanations for why interruption of glucose processing and ATP production might retard aging. One possibility relates to the ATP-making machinery's emission of free radicals, which are thought to contribute to aging and to age-related diseases by damaging cells. Reduced operation of the machinery should limit their production and thereby constrain the damage.

Another hypothesis suggests that decreased processing of glucose could indicate to cells that food is scarce and induce them to shift into an anti-aging mode that emphasizes preservation of the organism over such luxuries as growth and reproduction.

A. The world's one and only rotating boat lift, The Falkirk Wheel, was opened in 2002 in Scotland. It was an ambitious Millennium Link project constructed to restore navigation across Scotland by bringing together the historic waterways of the Forth and Clyde and Union Canals.

B. The biggest challenge of the project is the fact that the Forth and Clyde Canal is situated 35 metres below the level of the Union Canal. Historically, the two canals were linked near Falkirk by a series of 11 locks. The link was cut when this was removed in 1933.

C. Many ideas and concepts were submitted for the project. A concept for the massive spinning steel boat lift that would become The Falkirk Wheel was eventually chosen as the winner. The structure's shape is said to have been influenced by man-made and natural elements, including a Celtic double-headed axe, a ship's massive propeller, whale ribcage, and fish spine.

D. The components of The Falkirk Wheel were constructed at Butterley Engineering's Steelworks in Derbyshire and assembled 400 km from Falkirk. The structure was then dismantled and brought to Falkirk in 35 lorries, before being bolted back together on the ground and raised into place in 5 big pieces by crane. To make the structure more robust, the steel components were bolted together rather than welded together.

E. The Falkirk Wheel has two sets of opposing axe-shaped arms, at about 25 metres apart to a fixed central spine.

F. Two water-filled gondolas, each diametrically opposed and having a capacity of 360,000 litres, are fitted between the ends of the arms. Whether or not they are hauling boats, these gondolas always weigh the same. Floating objects displace their own weight in water. As a result, when a boat enters a gondola, the volume of water exiting the gondola is equal to the weight of the boat. This maintains the Wheel's balance, allowing it to rotate through 180 degrees in 5.5 minutes while consuming relatively less energy.

G. Boats requiring lifting enter the canal basin at the level of the Forth and Clyde Canal, then the Wheel's lower gondola. Two hydraulic steel gates are raised to isolate the gondola from the canal basin's water. After that, the water between the gates is pumped out. A hydraulic clamp that stops the Wheel's arms from moving while docked is released, allowing the Wheel to turn. The central axle is then rotated by a 10-motor array in the central machine room. The axle links to the Wheel's outer arms, which begin rotating. A simple gearing arrangement keeps the gondolas upright as the wheel turns. Two 8-metre-wide cogs orbit a fixed inner cog of the same width, connected by two smaller cogs that go in the opposite direction as the outer cogs, ensuring that the gondolas are constantly level. The boat passes directly onto the aqueduct, 24 metres above the canal basin, when the gondola reaches the top.

H. A pair of locks provide the final 11 metres of elevation required to access the Union Canal. Because of the historically significant Antonine Wall, the Wheel could not be built to elevate boats over the entire 35-metre distance between the two canals. Boats pass through a tunnel beneath the wall, through the locks, and onto the Union Canal.

A. According to the latest figures, the majority of the world's population is now bilingual or multilingual. In the past, such children were considered to be at a disadvantage compared with their monolingual peers. Over the past few decades, however, technological advances have allowed researchers to look more deeply at how bilingualism interacts with and changes the cognitive and neurological systems.

B. Research shows that when a bilingual person uses one language, the other is active at the same time. Long before a word is finished, the brain's language system begins to guess what that word might be. For bilingual people, this activation is not limited to a single language. Some compelling evidence for this phenomenon, called language co-activation, comes from studying eye movements. A Russian-English bilingual asked to pick up a marker from a set of objects would look more at a stamp than someone who does not know Russian, because the Russian word for stamp, marka, sounds like marker.

C. Having to deal with this persistent linguistic competition can result in difficulties. Knowing more than one language can cause speakers to name pictures more slowly and can increase tip-of-the-tongue states. As a result, the constant juggling of two languages creates a need to control how much a person accesses a language at any given time. For this reason, bilingual people often perform better on tasks that require conflict management. In the classic Stroop Task, people see a word and are asked to name the colour of the word's font. Bilingual people often excel at tasks such as this, which tap into the ability to ignore competing perceptual information and focus on the relevant aspects of the input. Bilinguals are also better at switching between two tasks.

D. It also seems that the neurological roots of the bilingual advantage extend to brain areas more traditionally associated with sensory processing. When researchers play the same sound to monolingual and bilingual adolescents in the presence of background noise, the bilingual listeners' neural response is considerably larger, reflecting better encoding of the sound's fundamental frequency.

E. Such improvements in cognitive and sensory processing may help a bilingual person process information in the environment, and help explain why bilingual adults acquire a third language better than monolingual adults master a second language.

F. Research also indicates that bilingual experience may help keep cognitive mechanisms sharp by recruiting alternate brain networks to compensate for those that become damaged during aging. Older bilinguals enjoy improved memory relative to monolingual people. In a study of over 200 patients with Alzheimer's disease, bilingual patients reported initial symptoms an average of five years later than monolingual patients.

G. Furthermore, the benefits associated with bilingual experience seem to start very early. In one study, researchers taught seven-month-old babies that when they heard a tinkling sound, a puppet appeared on one side of a screen. Halfway through, the puppet began appearing on the opposite side. Only the bilingual babies were able to successfully learn the new rule.