OA: 26E, 27D,28C,29D,30C
Answer to Question 26
In choice A, the introductory clause beginning Based on modifies scholars, the noun that immediately follows it: in other words, A says that scholars were based on the accounts of various ancient writers. Choice B is awkward and imprecise in that the referent for the pronoun it is not immediately clear. C and D are also wordy and awkward, and in D By the accounts... they used is an unidiomatic and roundabout way of saying that scholars used me accounts. E, the best choice, is clear and concise; it correctly uses a present participle (or "-ing" verb) to introduce the modifier describing how the scholars worked.
Answer to Question 27
In A, the they after because is ambiguous; it seems illogically to refer to Formulas because they and Formulas are each the grammatical subject of a clause and because the previous they refers to Formulas. In A and B, do not apply to... in the same way as they do to is wordy and awkward. D, the best choice, says more concisely in the same way as to. Also in B, because they refers to formulas, the introductory clause states confusedly that the formulas are growing. In C and E, subject to the [same] applicability of... is wordy, awkward, and imprecise; furthermore, are is preferable either before or after established big businesses to complete the comparison. Finally, the referent of they is not immediately clear in E.
Answer to Question 28
In choices A and B, rates of is incorrect; when rates means "prices charged," it should be followed by for. Also in B, are a force for does not accurately convey the meaning that the soaring rates are actually forcing cutbacks in the present. In A and E, it is redundant to say that soaring rates have risen. Similarly, the word rises makes D redundant. C, the best choice, is idiomatic and concise, and it correctly uses the progressive verb form are forcing to indicate an ongoing situation.
Answer to Question 29
D, the best choice, correctly follows estimated with to be. The other choices present structures that are not idiomatic when used in conjunction with estimated. Choices B, C, and E all mismatch the singular verb provides with its plural subject, fragments, and in choices C and E, what was is unnecessary and wordy. In choice C, the use of the verb phrase estimated that it is produces an ungrammatical sentence.
Answer to Question 30
The best choice is C because it uses the idiomatically correct expression distinguishes between x and y and because it provides a structure in which the relative clause beginning which may be violent clearly modifies mood swings. The other choices use distinguishes in unidiomatic constructions. Additionally, their in A is intrusive and unnecessary, and the modifier of mood swings in B and D (perhaps violent) is awkward and less clear than the more developed clause which may be violent.