[求助]新题 13套中的一题

Q32:

To develop more accurate population forecasts, demographers have to know a great deal

more than now about the social and economic determinants of fertility.

1. have to know a great deal more than now about the social and economic

2. have to know a great deal more than they do now about the social and economical

3. 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 economical

答案说选E，我觉得than now不太好吧，我选的D,请大家帮忙分析

楼主确定选E吗？would have to know a great deal more than now about the social and economical，

因为economical，我一开始就把B,C,E给排了，然后也选了D

E实在没有道理.

more than they do, do需要补出。

economic is correct!!!     

economical实在不合理。

比较结果要补出动词。

我选D。

vote for D

同意楼上两位的解释