2010年12月英语四级考试全真预测试卷(1)

　　Part I Writing (30 minutes)

　　Directions： For this part， you are allowed 30 minutes to write a composition one topic： City Problems. You should write at least 120 words following the outline given below in Chinese：

　　1. 越来越多的人涌入大城市，有些问题随之产生

　　2. 比较明显的大问题有……

　　3. 我对这种现象的想法

　　City Problems

　　Part II Reading Comprehension (Skimming and Scanning) (15 minutes)

　　Directions： In this part， you will have 15 minutes to go over the passage quickly and answer the questions on Answer Sheet 1.For questions 1-7， mark

　　Y (for YES) if the statement agrees with the information given in the passage;

　　N (for NO) if the statement contradicts the information given in the passage;

　　NG (for NOT GIVEN) if the information is not given in the passage.

　　For questions 8-10， complete the sentences with the information given in the passage.

　　Scientists Weigh Options for Rebuilding New Orleans

　　As experts ponder how best to rebuild the devastated (毁坏)city， one question is whether to wall off—or work with—the water.

　　Even before the death toll from Hurricane Katrina is tallied， scientists are cautiously beginning to discuss the future of New Orleans. Few seem to doubt that this vital heart of U.S. commerce and culture will be restored， but exactly how to rebuild the city and its defenses to avoid a repeat catastrophe is an open question. Plans for improving its levees and restoring the barrier of wetlands around New Orleans have been on the table since 1998， but federal dollars needed to implement them never arrived. After the tragedy， that‘s bound to change， says John Day， an ecologist at Louisiana State University (LSU) in Baton Rouge. And if there is an upside to the disaster， he says， it’s that ‘now we’ve got a clean slate to start from.“

　　Many are looking for guidance to the Netherlands， a country that， just like bowl-shaped New Orleans， sits mostly below sea level， keeping the water at bay with a construction of amazing scale and complexity. Others， pointing to Venice‘s long-standing adaptations， say it’s best to let water flow through the city， depositing sediment to offset geologic subsidence—a model that would require a radical rethinking of architecture. Another idea is to let nature help by restoring the wetland buffers between sea and city.

　　But before the options can be weighed， several unknowns will have to be addressed. One is precisely how the current defenses failed. To answer that， LSU coastal scientists Paul Kemp and Hassan Mashriqui are picking their way through the destroyed city and surrounding region， reconstructing the size of water surges by measuring telltale marks left on the sides of buildings and highway structures. They are feeding these data into a simulation of the wind and water around New Orleans during its ordeal.

　　”We can‘t say for sure until this job is done，“ says Day， ”but the emerging picture is exactly what we’ve predicted for years.“ Namely， several canals—including the MRGO， which was built to speed shipping in the 1960s—have the combined effect of funneling surges from the Gulf of Mexico right to the city‘s eastern levees and the lake system to the north. Those surges are to blame for the flooding. ”One of the first things we’ll see done is the complete backfilling of the MRGO canal，“ predicts Day， ”which could take a couple of years.“

　　The levees， which have been provisionally repaired， will be shored up further in the months to come， although their long-term fate is unclear. Better levees would probably have prevented most of the flooding in the city center. To provide further protection， a mobile dam system， much like a storm surge barrier in the Netherlands， could be used to close off the mouth of Lake Pontchartrain. But most experts agree that these are short-term fixes.

　　The basic problem for New Orleans and the Louisiana coastline is that the entire Mississippi River delta is subsiding and eroding， plunging the city deeper below sea level and removing a thick cushion of wetlands that once buffered the coastline from wind and waves. Part of the subsidence is geologic and unavoidable， but the rest stems from the levees that have hemmed in the Mississippi all the way to its mouth for nearly a century to prevent floods and facilitate shipping. As a result， river sediment is no longer spread across the delta but dumped into the Gulf of Mexico. Without a constant stream of fresh sediment， the barrier islands and marshes are disappearing rapidly， with a quarter， roughly the size of Rhode Island， already gone.

　　After years of political wrangling， a broad group pulled together by the Louisiana government in 1998 proposed a massive $14 billion plan to save the Louisiana coasts， called Coast 2050 (now modified into a plan called the Louisiana Coastal Area project)。 Wetland restoration was a key component. ”It‘s one of the best and cheapest hurricane defenses，“ says Day， who chaired its scientific advisory committee.

　　Although the plan was never given more than token funding， a team led by Day has been conducting a pilot study since 2000， diverting part of the Mississippi into the wetlands downstream of the city. ”The results are as good as we could have hoped，“ he says， with land levels rising at about 1 centimeter per year—enough to offset rising sea levels， says Day.