Read the article and select the best answer. Article: Supply and demand is perhaps one of the most basic concepts of economics and it is the backbone of a market economy. Demand refers to how much of a product or service is desired by buyers. The quantity demanded is the amount of a product people are willing to buy at a certain price; the relationship between price and quantity demanded is known as the demand relationship. Supply represents how much the market can offer. The quantity supplied refers to the amount of a certain goods producers are willing to supply when receiving a certain price. The relationship between price and how much of a goods or service is supplied to the market is known as the supply relationship. Price, therefore, is a reflection of supply and demand. The law of demand states that, if all other factors remain equal, the higher the price of a product, the fewer people will demand that product. The amount of goods that buyers purchase at a higher price is less as the price of a product goes up, so does the opportunity cost of buying that product. Like the law of demand, the law of supply shows the quantities that will be sold at a certain price. But unlike the law of demand, the supply relationship shows an upward slope. This means that the higher the price, the higher the quantity supplied. Producers supply more at a higher price because selling a higher quantity at a higher price increases the whole income. Now that we know the laws of supply and demand, let's turn to an example to show how supply and demand affect price. Imagine that a CD of your favorite band is sold for $20. Because the record company's previous analysis showed that consumers will not demand CDs at a price higher than $20, only ten CDs were sold because the opportunity cost is too high for suppliers to produce more. If, however, the ten CDs are demanded by 20 people, the price will then rise. As a result, the rise in price should cause more CDs to be supplied as the supply relationship shows that the higher the price, the higher the quantity supplied. If,... Question: We know from the passage that changes in the prices of product cause changes in _ . Options: A: income and expense B: invention and production C: market and society D: supply and demand
D

Read the article and select the best answer. Article: The history of the Winter Games, however, has been even more troubled than that of the Summer Games. Until 1924 all the winter sports competitions, held every four years from 1901 to 1917 and again in 1922, had been in the Scandinavian countries - Sweden, Norway and Finland. The sportsmen of these countries believed that the Winter Games could only be held in the Scandinavian way. Coubertin, himself, was against a separate Winter Olympics as he felt that they would cause trouble within the Olympic movement. However, as winter holidays in the Alps became more and more popular, so did the idea of a truly international Winter Games. The first Winter Olympics were held in Chamonix in 1924, though they were only recognized by the International Olympic Committee as "Olympic" two years later in 1926. Although there were many arguments before them, the first Games were a success, but the problems did not end there. In 1935, it was decided by the IOC that ski teachers could not compete in the Olympics because they were professionals. This caused a big argument between the IOC and the International Ski Federation, who agreed with the ski teachers. However, war came and with it an end to the discussions. When the war was finally over, the Winter Games were started up again, as before, in St Moritz in 1948 and the crisis had passed. Question: The above passage mainly discusses_. Options: A: the birth of the Winter Olympics B: the problems of the Winter Olympics C: the history of the Winter Olympics D: the necessity for a separate Winter Olympics
C

Read the article and select the best answer. Article: Nearly a quarter century after a German boy threw a message in a bottle off a ship in the Baltic Sea, he's received an answer. A 13yearold Russian, Daniil Korotkikh, was walking with his parents on a beach when he saw something lying in the sand. "I saw that bottle and it looked interesting, " Korotkikh told The Associated Press on Tuesday."It looked like a German beer bottle and there was a message inside." It said, "My name is Frank, and I'm five years old.My dad and I are travelling on a ship to Denmark.If you find this letter, please write back to me, and I will write back to you." The letter, dated 1987, included an address in the town of Coesfeld. The boy in the letter, Frank Uesbeck, is now 29.His parents still live at the letter's address. The Russian boy and the German man met each other earlier this month through an Internet video link.The Russian boy said he did not believe that the bottle actually spent 24 years in the sea.He believed it had been hidden under the sand where he found it for a long time. Uesbeck was especially happy that he was able to have a positive effect on a life of a young person far away from Germany."It's really a wonderful story, " he said."And who knows? Perhaps one day we will actually be able to arrange a meeting in person." Question: According to the text, which of the following statements is TRUE? Options: A: Korotkikh's parents still live in the town of Coesfeld. B: The German boy did not believe that the bottle actually spent 24 years in the sea. C: Frank Uesbeck and Daniil Korotkikh have met each other in person. D: Daniil Korotkikh and Frank Uesbeck have got in touch with each other.
D