To develop more accurate population forecasts, demographers have to know a great deal more than now about the social and economic determinants of fertility.
A have to know a great deal more than now about the social and economic
B have to know a great deal more than they do now about the social and economical
C would have to know a great deal more than they do now about the social and economical
D would have to know a great deal more than they do now about the social and economic
E would have to know a great deal more than now about the social and economical
My question is about the conditional construction. Can someone introduce this tense systematically? In this question, OG said this sentence is a hypothetical situation so it should use conditional construction, but I cannnot understant. I can understand the Manhattan said we should use would do when we want to express the future but the situation in whole sentence is past.
Thanks in advance!
A have to know a great deal more than now about the social and economic
B have to know a great deal more than they do now about the social and economical
C would have to know a great deal more than they do now about the social and economical
D would have to know a great deal more than they do now about the social and economic
E would have to know a great deal more than now about the social and economical
My question is about the conditional construction. Can someone introduce this tense systematically? In this question, OG said this sentence is a hypothetical situation so it should use conditional construction, but I cannnot understant. I can understand the Manhattan said we should use would do when we want to express the future but the situation in whole sentence is past.
Thanks in advance!
