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
4. would have to know a great deal more than they do now about the social and economic
5. would have to know a great deal more than now about the social and economical

答案是E，我觉得用economical 不对吧，另外请问这里需要用would吗？

E (economical)是不对的.不是题写错了, 就是答案给错了.

AD中,D好些. D补的全点比A.

用不用would,从原文中看不出来. 也就是说,没有不能用would的理由.