2009年12月英語四級(jí)全國統(tǒng)一模擬沖刺試卷

　　Questions 47 to 56 are based on the following passage.

　　The economic costs of noise are several. Airports are currently operating at less than 47 because of noise regulations which restrict their hours of operation. For instance, at Washington’s National Airport no jet traffic is allowed from 11 pm to 7 am. Other airports restrict the use of certain runway. One estimate is that noise 48 reduce possible airport use by 20 percent.

　　The 49 cargo trade is especially affected by night restrictions.

　　In the case of airports, jet engines may be 50 to reduce their noise level, or insulation from air traffic noise may be provided by the purchase of land around airports or the insulation of buildings.One estimate is that $5.7 billion would be required to 51 all existing jet engines with noise control devices. However, 52 the current state of the art, even taking this step will not reduce noise levels at all points to 53 values. Some combination of methods is probably necessary.

　　If all aircraft were made quieter by existing methods, there would be a number of economic benefits. An increase in airport capacity would 54 . Property values near airports might rise. Transportation costs to and from airports could be reduced since the airports now could be located closer to population center.

　　Much research still needs to be done on the economic 55 of noise reduction and noise effects.Although some of the effects of nose pollution are known, more must be discovered about its effects on health, productivity, property values and the quality of life. 56 , the cost of noise pollution control to the economy as a whole needs to be investigated.

　　注意：此部分試題請(qǐng)?jiān)诖痤}卡2 上作答。

　　A) identification

　　B) equip

　　C) profitable

　　D) capacity

　　E) pollution

　　F) restrictions

　　G) transformed

　　H) significant

　　I) furthermore

　　J) acceptable

　　K) modified

　　L) accordingly

　　M) considering

　　N) occur

　　O) aspects