Passage One

Many people believe that taking vitamin supplements is the best safeguard against the dangers of an incomplete diet, but this should be a last resort rather than a way out of a problem. Even if there is a genuine need for extra vitamins, then sooner or later the question arises “which ones do I need，how much of them, and how often?” There is really no simple answer to this question. The Food Standards Committee suggests in their recent report to the government that we do not need any extra vitamins. They say that they are “not necessary for a healthy individual eating a normal diet”. Whilst few of us would challenge their authority on the subject of nutrition, it is, perhaps, pertinent to ask the question “how many of us are healthy, and what is a normal diet?” There is an element of doubt in many minds about these two aspects and though few people are familiar with the wording of the Food Standards Report they do wonder instinctively if they areeating the right things. The blame for faulty eating habits is often placed at the door of the ubiquitous junk and convenience foods. As we have seen, some of these are not the criminals they are made out to be. White bread is only slightly less nutritious than brown bread and frozen vegetables can be almost as “fresh” as fresh food. There are very few foods which can really be described as pure rubbish. Many pre-packed foods contain too much sugar and we would all benefit by avoiding these, but most tinned, processed and dried foods contain useful amounts of fat, protein, carbohydrate, vitamins and minerals. The addition of a small amount of fruit or a side salad to convenience foods such as pizzas or hamburgers can turn a snack into a well-balanced meal.

“Junk” food is difficult to define. White sugar is probably the nearest contender for the title. It contains plenty of calories for energy but not much else, and is often described as an “empty calorie” food. Alcohol is also high in calories, but beer and wine contain some of the B vitamins and wine is a good source of iron, so even a teetotaler could not describe all alcohol as useless, nutritionally speaking. Calories measure the energy we derive from the food we eat, and sugar and alcohol are sometimes described as having a high energy density. There is a limit to the amount of energy we need each day (2,000～2,200 calories is the average for women and 2,500-3,000 for men) and if we eat too much sugar and alcohol there is no appetite left for the vitamin-rich foods we need—fish, meat, fruit and vegetables. Buying vitamins can be predicted by psychological as well as nutritional motives and it is prudent to investigate why we think we need them and what benefits we expect from them before we rush off to the health shop to make our purchases.

Questions 1-5 are based on Passage One.

Paragraph Ten

    Bats emit a very high frequency sound and listen for the echo that bounces off objects. The difference in time between emitting the sound and hearing the echo allows the bat to build up a mental “picture” of its environment. Homing pigeons can fly back to their home lofts by using the Earth’s magnetic field to navigate.

The animals with s___powers.

Since their first appearance on earth, men have gathered information and have attempted to pass useful ideas to other men. 46.The carving of word-pictures on the walls of ancient caves as well as hieroglyphics on stone tablets represent some of men's earliest efforts to convey information.Scenes of hunting, maps of battles, and the stories of heroes were put down for all to see.

But as civilizations grew more complex, better methods of communication were needed. The written word, carrier pigeons, the telegraph, andmany other devices carried ideas faster and faster from man to man. 47.In recent years one type of machine, the electronic computer, has become increasingly important in the lives of all the people in the industrialized nations of the world.Computers are now widely used aids for communication, calculation, and other activities. Their effect becomes more important every day.

Man has always been interested in extending the range of his senses and the power of his mind. Through the years, he has invented many instruments to help him see better and understand more. 48.The telescope, for example, was invented to allow him to look at faraway objects. To see the very small things in the world, the microscope was developed.Radio, telephone, and telegraph are means by which man has extended the range of his senses of hearing and speech.

While developing his power of thought, man first began to identify and count objects. He began to ask the questions “What is it?” and “How many?”. It was a long time ago that this numbering and comparing of things began.

49.New ways of helping with counting and recording information evolved. Marks of different kinds were taken to represent certain quantities, and other marks were taken to represent relationships between quantities.

New devices to aid in the manipulation of numbers were developed.

Electronic computers are among the fastest and most useful instruments for sorting and comparing in use today. 50.Computers provide the means for greater speed and accuracy in working with ideas than had previously been possible. With the development of these new tools, it is as if man has suddenly become a millionaire of the mind.

Although man has been growing mentally richer ever since he started to think, the electronic computer allows and will continue to allow him to perform tremendous “mental” tasks in a relatively short time. Great scientists of the past produced ideas which were the basis for great advances, but their ideas sometimes had to wait for years before they were understood sufficiently well to be of practical use. With the computer, the ideas of today’s scientists can be studied, tested, distributed, and used more rapidly than ever before.

51.Old lines and methods of communication do not work easily or efficiently with as much information as we have now. The repeated actions of preparing， sorting, filling, distributing, and keeping track of records and publications can be as troublesome as calculating. Errors occur because men grow tired and can be distracted.

The basic job of computers is the processing of information. For this reason computers can be defined as devices which accept information, perform mathematical or logical operations with the information, and then supply the results of these operations as new information.

Paragraph Nine

    Some air pollutants can cause cancer, problems with having children and other very serious illnesses as well as environmental damage. Air pollutants have killed people swiftly when large quantities were released; the 1984 release of methyl isocyanate at a pesticide-manufacturing plant in Bhopal, India, killed approximately 4,000 people and injured more than 200,000.

Air pollutants can be f__.

Paragraph Eight

   Studies have shown that people forced to share workspaces reported feeling marginalized, experienced more distractions, negative relationships and uncooperative behavior, not to mention feeling like their supervisors were being less supportive. Studies also find that open plan offices can have some negative psychological effects, reducing employee satisfaction, focus, and their feelings of having privacy at work.

Open office e___and its negative effects.

Paragraph Seven

Spinach may cause Alzheimer’s disease in at-risk people, research suggests. The salad leaf’s iron-rich content may damage the brain similar to how the compound causes metal to rust, according to the researchers. People with high levels of iron, which has previously been associated with Alzheimer’s, are more likely to experience rapid cognitive decline, a study found.

Iron-rich v   may lead to Alzheimer’s disease.

Paragraph Six

    Driving for more than two hours a day negatively affects IQ levels, scientists have warned. In what might come as unwelcome news for middle-aged commuters, a recent study found that long periods behind the wheel could speed up the effects of age on the brain because the mind is less active on long car journeys.

Driving for a long t   may dull your mind.

Paragraph Five

    Economists long ago point out why it is bad for a single firm to dominate a market. They believe that monopolists can set prices almost asthey please. Worse, if a company has no fear of competition, it needn’t worry too much about keeping customers happy and creating new and better products.

The c____of monopoly.

Paragraph Four

  Recent research suggests that tea-producing areas in some places, notably East Africa, could decline by as much as 55 percent by 2050 as temperatures change. Tea pickers are also feeling the impacts of climate change. During harvest season, increased air temperatures are creating an increased risk of heatstroke for field workers.

The effect of r   temperatures on tea production.

Paragraph One

When you lose an hour of sleep, it decreases your well-being, productivity, health, and ability to think the following day. One of the most influential studies of human performance found that top performers slept 8 hours and 36 minutes per day. You are simply a different person when you operate on insufficient sleep.

Insufficient sleep may lead to p   performance.

Paragraph Two

   Type D personalities usually have a low self-esteem and a great fear of disapproval. Negative emotions such as worrying, stress, depression and anger visit type D personalities more often. A small event that is usually overlooked by others can bother a type D a lot and even ruin his mood.

A c___type and its features.