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
20,000 ten times +n 这个名字怎么着也应该是个number吧,或者amount, 怎么直接就是population呢?我觉得20,000和population比较对象不对等啊~~~~ 还是说CDE都错在ten times more than上面???