[求助]GWD1-32

maimai2009

In the correct answer D, why use "should have to" instead of using " have to"?



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

rachelchen52

"To develop more accurate..."这里暗示应该是虚拟吧~所以 would have to

maimai2009

以下是引用rachelchen52在2008-12-15 5:06:00的发言：

"To develop more accurate..."这里暗示应该是虚拟吧~所以 would have to

To develop是目的状语吧，怎么暗示虚拟呢？哪里有这个说法的？

谢谢了

rfanrfan

have to know a great deal：不得不知道很多（表示已经知道了）

would have to know a great deal:不得不去知道很多（表示还不知道）

maimai2009

谢谢两位,但我还是觉得好像没解释到位...

free1234

为什么不选economic？economical不是经济、合算的意思吗