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 economic
have to know a great deal more than they do now about the social and economical
would have to know a great deal more than they do now about the social and economical
would have to know a great deal more than they do now about the social and economic
would have to know a great deal more than now about the social and economical
more than 前后是两独立的句子，翻译为不仅仅或不只是，they do 不能省，省了导致比较混乱。虚拟是将来发生，目前还没发生。
所以选D，作者: chriswendy35 时间: 2010-8-17 06:46
demographers have to know a great deal more than now
补助动词是防止主语比较，宾语比较等发生错乱
但这里只有一个主语，并且是自己跟自己比，应该是可以省略
不过这点我不确定
不过would have to我还是不认同
将来时本来就是目前没发生的。不然所有将来时都应该用虚拟语气了。
我仍然不认为To graduate, I have to pass all core courses.这种表达有错作者: nymphl 时间: 2010-8-18 06:44
1. To graduate, I have to pass all core courses.
2. To graduate, I would have to pass all core courses.
意思不一樣
1. 如果你pass所有core courses, 你非常確定你會graduate
2. 如果你pass所有core courses, 你不是非常確定你會graduate作者: chriswendy35 时间: 2010-8-18 20:02
谢谢。这个我以前一点都不知道。我还以为是个错误表达。
那么至少D的语法是没有问题了
不过我还有个疑问，虽然有点咬文嚼字的嫌疑，呵呵
To graduate的确是个不容易确定的动词，是个结果。我的意思是有可能graduate，也有可能不graduate，如果仅凭pass所有科目的话
