扫描二维码，直接登录
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
还没有题目讲解（毕出老师会陆续发布对官方考题的解读，请保持关注）。
归因：忘记规则
amount指不可数名词；可数用quantity或number
其次C中amount和population意思重复，没必要
登录 或 注册 后可以参加讨论