sosGWD第一套Q32答案为何是E而不是B?

violetcxd

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

violetcxd

?有没有XDJM给我些提示啊?

aqualon

they在这里指代demographers,所有从整个句子的意思上讲“demographers做了一些繁殖力的社会和经济性的决定因素“，这样就不合逻辑了。而且这里运用了同样一件事在不同的时间点做了比较，所以要用过去时。所以E是正确的