标题: 关于虚拟语气 [打印本页] 作者: glw1900 时间: 2011-11-15 23:20 标题: 关于虚拟语气 To develop more accurate p p p population forecasts, , demographers have to know a great deal more than now about the social and economic determinants of fertility. (A) have to know a great deal more than now about the social and economic i l d i (B) have to know a great deal more than they do now about the social and economical (C) would have to know a great deal more than they do now about the social and economical (D) would have to know a great deal more than they do now about the social and economic (E) would have to know a great deal more than now about the social and economic