The well-known Red List that details which species are threatened with extinction is inaccurate, according to a new assessment. It concludes the list fails to reflect the true threat to species, by not taking full account of the threat posed by people.
　　The Red List, which is compiled by the World Conservation Union (IUCN), gauges a species’ risk of extinction mainly on the basis of its population size, rate of decline and geographic range.
　　But Alexander Harcourt and Scan Parks at the University of California, Davis, argue that this is not enough. They compare an endangered species to a house that has been left unlocked. The house is vulnerable to burglary, but it only becomes threatened when there is a burglar nearby.
　　In the same way, a small population of animals susceptible to extinction only becomes actively threatened when it is being poached or its habitat is destroyed. Harcourt and Parks advocate modifying he Red List criteria to include local human population density.
　　Although a large number of people nearby may not in itself be a threat, they argue that hunting pollution and habitat destruction, for example, are all likely to increase as people encroach on wildlife. What is more, data on human density is readily available. We have the numbers, why not use them? says Harcourt.
　　To illustrate their point, the researchers reassessed 200 primate species from the 1996 Red List, They found that 17 species designated as being at relatively low risk by the Red List should now be reassigned as high priority.
　　Contrary to the expectations of many, the researchers also found that two high-profile species, the gorilla and the pygmy chimpanzee, or bonobo, should be downgraded to a lower level of threat.
　　But Craig Hilton-Taylor, Red List Programme Officer based in Cambridge, England, says that theIUCN has already introduced a specific classification system for threats-such as human density. The system runs in parallel to the main Red List classification.
　　Besides, part of the Red List’s value is that you can make comparisons with past assessments, he says, and tweaking the criteria would make this impossible. Weve been asked by everyone, please don’ t change the system again, says Hilton-Taylor.
　　Harcourt maintains that making explicit threats part of the criteria is not only more accurate, it may also help highlight future problems. Matt Walpole, a conservation researcher at the University of Kent at Canterbury, England, agrees: Where population data is lacking, it might be a useful way of flagging up potentially threatened species. [417 words]
　　1. The Red List used to determine the risk of extinction a species may run by assessing all of the following, EXCEPT ______
　　A. human population data
　　B. the species’ population size
　　C. the species’ rate of decline
　　D. the geographic range of the species
　　2. An endangered species is compared to an unlocked house in order to show that ______
　　A. an unlocked house is vulnerable to burglary
　　B. an unlocked house is not threatened without a burglar nearby
　　C. no other comparisons are more intelligible than this one
　　D. the Red List fails to reflect the threat posed by people to rare species
　　3. In order to indicate the level of threat posed by people to rare species, _____ has/have been introduced.
　　A. a specific classification system
　　B. a more accurate assessment system
　　C. the Red List criteria
　　D. the Red List classification
　　4. The level of risk indicated by the Red List to each endangered species should be ______
　　A. downgraded
　　B. upgraded
　　C. reassessed
　　D. kept as it is
　　5. The proper title for this passage should be ______
　　A. Data on Human Density
　　B. Red Alert over Rare Species
　　C. Red List Classification
　　D. Potentially Threatened Species

难句透析：
 　　①It concludes Ethe list fails to reflect the true threat to species，by not taking full account of the threat(posed by people)]． 
　　【结构】主句主语“It”指前一句提到的“a new assessment”。方括号所标示的部分是“concludes”的宾语从句。圆括号所标示的过去分词短语用做后置定语，修饰“the threat”。 
　　【释义】该项评估的结论认为，由于没有充分考虑人所造成的威胁，这份红名单并未反映出对物种的真正威胁。 
　　②In the same way，a small population of animals[susceptible to extinction]only becomes actively threatened when l’it is being poached—or”its habitat is destroyed]． 
　　【结构】第一个方括号所标示的形容词短语用做后置定语，修饰“a small population of animals”。第二个方括号所标示的部分是“when”引导的时间状语从句，由“or”连接的两个分句并列而成。  考试大