作者：英吉
Africa's black rhino population in the mid-1970's numbered about 20,000, ten times the estimated population of 2,000 in 1997.
(A) the estimated population
(B) that of their estimated population
(C) more than the population's estimated amount
(D) more black rhinos than their population estimate
(E) more than that of their population's estimated amount
原文意思:一种动物的数量原来有2万头，是1997年的十倍。
题目分析：应该是以前的population和1997年的population进行的比较，A就是这两种population进行的比较，留着。B加上that比较对象就不对了，干掉。C是population何后面的amount进行比较了，比较对象仍然不对，干掉。D和E还多说了个more black rhinos，划线前面已经说过了，再说一次明显画蛇添足，干掉，更何况E也加了that，残疾选项中的战斗机！
