Option(E) is correct There are two issues being tested in this question. (1) The phrasing used in the original question (differentiated x with y) is not idiomatically correct and should be replaced by the correct idiom (differentiated between x and y) (2) In order to ensure clarity and improve flow, the sentence should be constructed so that the format is consistent: differentiated between X, {description of X}, and Y, {description of Y} A. the phrase differentiated latent semantic indexing...with vector space models is not idiomatically correct (i.e., the correct idiom is: differentiated between x and y) B. the phrase differentiated between latent semantic indexing...with vector space models is not idiomatically correct (i.e., the correct idiom is: differentiated between x and y) C. the phrase differentiated among implies that more than two objects are being compared, which is not true is this case; so, differentiated among is improperly used D. the phrase differentiated latent semantic indexing...and vector space models is not idiomatically correct (i.e., the correct idiom is: differentiated between x and y) E. the phrase differentiated between latent semantic indexing...and vector space models is idiomatically correct as it follows the idiom differentiated between x and

Option(B) is correct This sentence turns on an idiom: either to x or [to] y where both x and y must be parallel. The sentence should be: the Federal government...required either to bring...or [to] release Unfortunately, the current sentence incorrectly reads: the Federal government...required either to bring...or that the government must release. This is not parallel and is wrong. The correct sentence structure is: the Federal government is required either to bring charges against the individual being held, in which case he is entitled to a lawyer, or release him. Do not be thrown off by in which case he is entitled to a lawyer, which was inserted simply to make spotting the idiom and parallelism more difficult. The phrase in which case he is entitled to a lawyer is merely an elucidation of the preceding idea and is not another item that itself must be parallel. A. the sentence is not idiomatically correct (i.e., the phrase the Federal government...is required either to bring...or that the government must release is not idiomatically correct) B. the sentence correctly uses the idiom either to x or [to] y C. although the sentence follows the correct idiom either to bring...or to proceed, the phrase to proceed in releasing is not concise and can be replaced by [to] release D. the sentence is not idiomatically correct (i.e., the phrase the Federal government...is required either to bring...or the government must release is not idiomatically correct) E. the sentence is not idiomatically correct (i.e., the phrase the Federal government...is required either to bring...or they must release is not idiomatically correct); they, which is a plural pronoun, does not agree with the subject the Federal government, which is singular

Option(C) is correct There are three problems with the sentence: (1) The pronoun them (which is a plural pronoun) improperly refers back to the National Security Agency (which is a singular noun). As the sentence is currently constructed, one could construe the meaning as United States Congressmen were allowed to eavesdrop when the intention is that the Congressmen authorized the National Security Agency to eavesdrop. (2) It is imperative that the two powers that the Congressmen granted the National Security Agency appear in parallel: to eavesdrop ... and [to] pass along. (3) evidence from the calls is somewhat imprecise and can be improved by saying evidence from those calls, which more explicitly refers back to the calls on which the National Security Agency eavesdropped. A. The pronoun them (which is a plural pronoun) improperly refers back to the National Security Agency (which is a singular noun) B. The phrase the calls on which it eavesdropped is precise, but it is too wordy and could be replaced by those calls C. The singular pronoun it properly refers back to the singular noun National Security Agency; those calls is concise; to eavesdrop and [to] pass along are parallel D. The pronoun them (which is a plural pronoun) improperly refers back to the National Security Agency (which is a singular noun); the two powers that the Congressmen granted the National Security Agency are not parallel (i.e., to eavesdrop ... andpassing along); to be is wordy and unnecessary E. The two powers that the Congressmen granted the National Security Agency are not parallel (i.e., to eavesdrop ... and passing along); to be is wordy and unnecessary

Option(E) is correct There are two main issues being tested in this problem. (1) The subject (executive managers, which is plural) must be referred to with a plural pronoun (them not it) (2) The Board of Directors planned to do two things: to fire the current executive managers and [to] replace them. These two plans must be parallel. The resulting sentence is: the Board of Directors planned to fire the current executive managers...and [to] replace where the [to] is understood since replace is in the infinitive form. A. the phrase the Board of Directors planned to fire...and in replacing is not parallel B. the singular pronoun it cannot refer to a plural subject (i.e., the current executive managers); the phrase to be replacing is not concise and should be replaced by to replace C. the singular pronoun it cannot refer to a plural subject the current executive managers D. the phrase the Board of Directors planned to fire...to replace lacks the word and, which is needed to clearly delineate between the two actions or plans that the Board announced