2013年12月英语四级考试真题答案卷二_第4页

Section C

Directions ： In this section' you will hear a passage three times. When the passage is read for the first time, you should listen carefully for its general idea. When the passage is read for the second time, you are required to fill in the blanks with the exact words you have just heard. Finally, when the passage is read for the third time, you should check what you have written.

注意：此部分试题请在答题卡1上作答。

Many college students today own personal computers that cost anywhere from $ 1 000 to perhaps $ 5 000 or more.  26  ,it is not uncommon for them to purchase  27  costing another several hundred dollars. Twenty years ago, computers were  28  ，but they were very large and extremely expensive. Few, if any, 29  purchased computers for home use. Over the years, the price of the "guts" of a computer —its memory一has declined to less than a thousandth of the price per unit of memory that prevailed twenty years ago. This is the main reason why computers cost so much less today than they used to. Moreover,  30  improvements have made it possible to  31  memory circuitry that is small enough to fit into the portable personal computers that many of us own and use.  32  , as the price of computation has declined the average consumer and business have spent more on purchasing computers.

33  , improved agricultural technology, hybrid (杂交）seeds,  34  animal breeding, and so on have vastly increased the amount of output a typical farmer can produce. The prices of goods such as meats and grains have fallen sharply relative to the prices of most other goods and services. As agricultural prices have fallen, many households have decreased their total expenses on food. Even though the  35  of a product purchased generally increases when its price falls, total expenses on it may decline.