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题库 / Prep2007E1-SC-66
Africa's black rhino population in the mid-1970's numbered about 20,000, ten times the estimated population of 2,000 in 1997.
the estimated population
that of their estimated population
more than the population's estimated amount
more black rhinos than their population estimate
more than that of their population's estimated amount
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population numbers 20000 in 1970，ten times the population of 2000 in 1997，ok
如果加入more than，population numbers 20000 in 1970，ten/nine times more than the population of 2000 in 1997，比较对象就是population对population，加了that of，比较population's amount的都是错的。
D，estimate是动词，被动式/形容词是estimated，名词是estimation，than their population estimate of 2,000，结构错误
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