单选题 By 2050 the world will have about 2 billion people aged over 60, three times ______ today.
  • A. as much as
  • B. as that of
  • C. as many as
  • D. as those of
【正确答案】 C
【答案解析】[解析] 本题是在考查倍数表达法和同级比较句。此类考题较为普遍。