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 economic
The question tests the concept of Modifiers, Comparison, and Conditional sentences.
“To develop more accurate population forecasts, demographers
have to know a great deal
more than now about the social and
economic determinants of fertility.”
We can identify three points in the question that need to be examined.
When we do a vertical scan of the options, we see that two options begin with “have to know” and three options begin with “would have to know”.
Two options end in ‘economical’ and three options end in ‘economic’.
Two options have the phrase “more than now” and three options have the phrase “more than they do now”.
The choice between ‘economic’ and ‘economical’ is simple. The word ‘economic’ is the adjective form of the word ‘economy’ and is the better choice in this sentence because the sentence discusses the “social and ….. determinants of fertility. The word ‘economical’ means avoiding waste or extravagance. It doesn’t fit into the sentence.
On this basis, we can eliminate
Options B and C.
To choose the best among Options A, D, and E, we can either use the rule of the Conditional sentence by choosing between the phrases ‘have to know’ and ‘would have to know’, or the rule of Comparison by choosing between the phrase “more than now’ and “more than they do now”.
Let us start with the rule of Comparison. The comparison should be between how much ‘demographers’ know now and how much the ‘demographers’ should know. The comparison will be complete only when the noun demographers is mentioned again or a pronoun is used to refer to them.
“demographers have to know a great deal more than now”
“demographers would have to know a great deal more than they do now”
It is only in the second construction that the comparison is complete.
On this basis, we can rule out
Options A and E.
The Conditional sentence starts with ‘if’. However, in this sentence, the condition is conveyed through the prepositional phrase “To develop more accurate population forecasts”.
The construction of a conditional sentence is as follows:
If + subject + verb in the past tense, Subject + would/could + verb in the present tense.
If demographers wanted to develop more accurate population forecasts,
they would have to know a great deal more than now about the social and economic determinants of fertility.
In this sentence too, that construction has to be maintained to make a proper conditional sentence. On this basis,
Option A can be ruled out.
Therefore, Option D is the most appropriate option.Jayanthi Kumar.
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Crackverbal Prep Team
www.crackverbal.com