The current account deficit, which measures not only trade in products and services but also investment flows between countries, have declined, leading some economists to predict the national deficit will also begin a decline.


A. which measures not only trade in products and services but also investment flows between countries, have declined, leading some economists to predict the national deficit will also begin a decline Incorrect

Sv error - The current account deficit singular, have plural

B. which not only measures trade in products and services but also investment flows between countries, has declined, leading some economists to predict that the national deficit will begin a decline also Incorrect

parallelism error - ..............not only measures trade.............but also investment flows..............

C. a measurement of not only trade in products and services but also investment flows between countries, has declined, leading some economists to predict that the national deficit will also begin a decline Correct

D. a figure not only measuring trade in products and services but also investment flows between countries, has declined, leading some economists to predict that the national deficit will also begin a decline Incorrect

parallelism error - ..............not only measuring trade.............but also investment flows..............

E. a measurement not only of trade in products and services but also investment flows between countries, has declined, leading some economists to predict that the national deficit will begin a decline also Incorrect

parallelism error - ..............not only of trade.............but also investment flows..............

VERITAS PREP OFFICIAL SOLUTION:

Whenever you see a "not only...but also" structure in a Sentence Correction problem you should treat it as a primary decision point: the items after "not only" and "but also" should be in parallel form. You can check for this by simply ignoring everything between "not only" and "but also," inclusive - if what remains is not a complete thought, you can eliminate that choice. Here that allows you to eliminate:

(B) "The current account deficit, which...investment flows"

(D) "The current account deficit, a figure...investment flows"

(E) "The current account deficit, a measurement...investment flows"

Note that even without this trick you should see that these choices are incorrect. In (B) the word that follows "not only" is a verb (measures) so to be correct the portion after "but also" would also have to have a verb; in (D) the same mistake is made with "measuring" after "not only" but not after "but also." And in (E) "not only" gets a preposition (of) but "but also" does not.

Between (A) and (C) there remains a simple Subject-Verb Agreement error: (A) features "have declined" while (C) uses "has declined." Since the subject is the singular "current account deficit" the verb "has" is correct, making (C) the correct answer.
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