That is what the economy is all about — making choices on how to use limited resources of money, manpower, machinery and materials, whether it involves a shopper deciding what to buy in the supermarket or a manufacturer deciding what line of goods to produce. Choices made in the economy involve a continuous tug-of-war between consumers and producers over price.

If many businesses are offering a product and there is plenty of it to satisfy the needs of all consumers, a producer will be forced to sell at a price not far above costs in order to keep from being stuck with a lot of unmarketable supplies. This is why, for example, prices for fresh fruit and vegetables drop during the summer months when such produce is in great number.

However, a low price — especially if it falls below what it costs a seller to make the goods — will discourage production, perhaps drive the high-cost producers out of business or force them to make something else. Again using an example from agriculture, farmers periodically plant less wheat or raise fewer cattle if the prices for those commodities give too little return for the costs involved.

On the other hand, if there is great demand for a product and supplies are tight, business will be able to raise prices, their profits will increase and they will invest in new equipment to increase output. Other firms may be attracted by the hopes of good profits to produce the scarce item, thus adding new competition.

That, in the simplest form, is the way the law of supply and demand works in free-market economy. Price becomes the guidepost, telling producers what they can expect to sell at a price that more than covers their costs. At the same time, posted prices tell the consumer what he can expect to pay.

26. small in amount or number (Para. 1)

27. the kind of (Para. 1)

28. goods, items available (Para. 2)

29. to prevent from happening (Para. 3)

30. at regular times (Para. 3)

31. profit from investment (Para. 3)

32. not enough of (Para. 4)

33. not easy to find or obtain (Para. 4)

34. it gives important information about (Para. 5)

35. to have enough money to pay something (Para. 5)

It was a great shock to me to discover that I had motor neuron disease. (46. I had never been very well co-coordinated physically as a child. I was not good at ball games, and my handwriting was the despair of my teachers.) But things seemed to change when I went to Oxford, at the age of 17. (47.I took up coxing and rowing. I was not boat race standard, but I got by at the level of inter-college competition.)

In my third year at Oxford, however, I noticed that I seemed to be getting clumsier, and I fell over once or twice for no apparent reason. But it was not until I was at Cambridge, in the following year, that my father noticed, and took me to the family doctor. He referred me to a specialist, and shortly after my 21st birthday, I went into hospital for tests.

The realization that I had an incurable disease, that was likely to kill me in a few years, was a bit of a shock. (48. How could something like that happen to me? Why should I be cut off like this? Not knowing what was going to happen to me, or how rapidly the disease would progress, I was at a loose end.) The doctors told me to go back to Cambridge and carry on with the research I had just started in general relativity and cosmology.But I was not making much progress, because I didn’t have much mathematical background. And, anyway, I might not live long enough to finish my Phd. I felt somewhat of a tragic character.

But shortly after I came out of hospital, I dreamt that I was going to be executed. (49. I suddenly realized that there were a lot of worthwhile things I could do if I were reprieved. In fact, although there was a cloud hanging over my future, I found, to my surprise, that I was enjoying life in the present more than before.) I began to make progress with my research, and I got engaged to a girl called Jane Wilde, whom I had met just about the time my condition was diagnosed. That engagement changed my life. It gave me something to live for. But it also meant that I had to get a job if we were to get married. I therefore applied for a research fellowship at Gonville and Caius College, Cambridge. To my great surprise, I got a fellowship, and we got married a few months later.

The fellowship at Caius took care of my immediate employment problem. (50. I was lucky to have chosen to work in theoretical physics, because that was one of the few areas in which my condition would not be a serious handicap.) And I was fortunate that my scientific reputation increased, at the same time that my disability got worse. This meant that people were prepared to offer me a sequence of positions in which I only had to do research without having to lecture.

Passage Nine

The reigning queen of all media in the US is talk-show host Oprah Winfrey. Her influence goes beyond her daily one-hour show into everything from the publishing business to the agricultural markets. Do you need proof? When Winfrey discusses an unknown author on her show, his book goes to the top of the best-seller charts.

Queen of t______.

Passage Ten

London’s underground railway will replace commuters’ sweaty odors with the gentle waft of perfume when it introduces a new air freshener into the world’s oldest subway. London has imported a powerful perfume, called Madeleine, from the Paris Metro. Madeleine will be used to mask the pungent smells of London’s underground.

Perfume masks c______ odors.

Passage Six

Several governments in Europe have decided that radical action is required to increase the number of women in the executive suite. Norway passed a law in 2003 that obliged all publicly listed firms to reserve 40% of the seats on their boards for women by 2008. Spain passed a similar law in 2007; France earlier this year.

The Netherlands is working on one.More women in b______ top.

Passage Seven

The business travel and meetings organization in America attributes the recent increase to rising airfares, fuelled by energy prices, constrained capacity and relatively strong demand, higher lodging rates, and growing corporate demansd. For example, it expects corporate spending on overseas trips to rise to $31.8 billion in 2011, a 9.1% increase on last year.

The price of t______ continues rising in America in 2011.

Passage Eight

The row over phone-hacking by journalists has led to the closure of the News of the World newspaper, and wider questions about press regulation, media ownership, the police, and relationships between politicians and journalists. It admitted intercepting voicemails in April after years of rumor that the practice was widespread.

Ethics in j______.

Paragraph Four

Scientists have found that life can survive in boiling pools of toxic water at Yellowstone National Park, something they did not think was possible. The fact that life can thrive in a boiling pool brings up all sorts of ideas about the origins of life. It may be that the first life on Earth was in the places humans might consider hospitable.

Finding life in unusual p______.

Paragraph Three

The IAEA, the UN nuclear watchdog, warned that the nuclear crisis triggered by Japan’s earthquake and tsunami is far from over. The lesson Germany learns from the Japanese nuclear disaster is that the earlier the exit, the better. Germany would turn to green and clean technologies and become a nuclear-free country.

Germany’s reflection on nuclear e ______.

Paragraph Five

“This type of meal, this fast food made with ground beef with a certain tomato sauce, fries does not strike me as a universal dream!” said Jean Glavany, France’s agriculture minister. “I want to spare Europeans this,” he said. “My struggle is cultural—what I have opposed and still oppose is the imperialism of a food model that wants to be the only model.”

The b______ over fast food.

Paragraph One

A 39-year-old woman, a patient in a psychiatric clinic had locked herself in a toilet with a knife. Police brought the dog Purzel when they learned the woman was a dog lover. As soon as the woman spotted Purzel sniffing through a crack in the door she dropped the knife and picked him up.

Hero dog p ______ a suicide.