GWD-10-Q36省略问题求证

大笑丸子

以下是引用黄公子在2008-8-12 10:39:00的发言：
再问一道省略的问题
GWD1-Q32:比較同類,麻煩字



To develop more accurate population forecasts, demographers have to know a great deal more than now about the social and economic determinants of fertility.

have to know a great deal more than now about the social and economichave to know a great deal more than they do now about the social and economicalwould have to know a great deal more than they do now about the social and economicalwould have to know a great deal more than they do now about the social and economicwould have to know a great deal more than now about the social and economical

答案：E
这里也是个省略问题有疑惑.more than前后主语谓语不是都相同么？
也有说这里would have to know和后面的谓语不一致，一个是虚拟，一个是现在发生动作，所以要补出do.是这样么？
那主语一致不是也要省略么？

这个为什么用would have to这个事态阿？

-- by 会员 nemo11 (2008/8/12 13:22:00)

问题是这个题应该是是选D啊～