帮忙GWD-1-Q32

kennypl

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

  怎么会是E呢...WOULD时态不对呀

[此贴子已经被作者于2006-10-11 12:42:38编辑过]

kennypl

顶..怎么没人帮忙啊...求助啊