参考答案：

　　Answer to Question 21

　　In choices A, C, and E, in attributing ... behavior modifies the perpetrators, producing the illogical statement that the perpetrators rather than the defense attorneys are attributing behavior to food allergies. Choice C is also wordy, and attributing ... as is unidiomatic in E. In the correct form of the expression, one attributes x, an effect, to y, a cause; or, if a passive construction is used, x is attributed to y. D avoids the initial modification error by using a passive construction (in which the attributors are not identified), but attributed x as the cause of y is unidiomatic. Choice B is best.

　　Answer to Question 22

　　C, the best choice, places not and but in such a way that the distinction between springing to life in a flash of inspiration and evolving slowly is logically and idiomatically expressed. A and B are faulty because, for grammatical parallelism, not in a flash... must be followed by but in..., not by a conjugated form of the verb.

　　Moreover, were slowly evolved is incorrect in B because evolve, in this sense of the word, cannot be made passive. Choices C, D, and E all correctly place not before spring. D, however, contains inconsistent verb tenses; E contains the faulty passive and an intrusive they.

　　Answer to Question 23

　　Because a count of women employed outside the home at any given time will be expressed by a single number, 160 the use of the plural noun numbers in choices A, B, and C is illogical. In A, the phrase grew by more than a thirty-five percent increase is redundant and wordy, since the sense of increase is implicit in the verb grew. In

　　C and E, the passive verb forms were raised and was raised are inappropriate because there is no identifiable

　　agent responsible for the raising of the number of women employed. In choice E, was raised by ... increase is

　　redundant. Choice D, which presents the comparison logically and idiomatically, is the best answer.

　　Answer to Question 24

　　In A, B, and C, the phrase being converted is awkward and redundant, since the sense of process indicated by being has already been conveyed by undergoing. A and D can be faulted for saying if rather than whether, since the sentence poses alternative possibilities, to sign or not to sign. Only E, the best choice, idiomatically completes whether with an infinitive, to sign, that functions as a noun equivalent of decision. Choice E also uses the noun conversion, which grammatically completes the phrase begun by undergoing.

　　Answer to Question 25

　　Choice C is best. The third verb phrase in the series describing bulls and cows should have the same grammatical form as the first two. Only choice C has a present participle (or "-ing" form) that is parallel with the two preceding verbs, receiving and fetching. Instead of the present participle, choices A and B use the past tense (excited), choice D uses an auxiliary verb (would excite), and choice E uses the past perfect tense (had excited). Additionally, the incorrect verb tenses in B and E are introduced by a pronoun, it, that lacks a logical noun referent.

　　Answer to Question 26

　　Choice B is the best answer. The sentence compares one thing, an adverse change in climate, to all other things in its class-- that is, to all the possible disasters that threaten American agriculture, therefore, the sentence requires the superlative form of the adjective, most difficult, rather than the comparative form, more difficult, which appears in choices A and D. In A and C, the use of maybe is unidiomatic, and difficult should be completed by the infinitive to analyze. Choice E is awkwardly phrased and, when inserted into the sentence, produces an illogical structure: the possibility ... is... the analysis that.

　　Answer to Question 27

　　Choices A and B present dangling modifiers that illogically suggest that Owen and Randolph, rather than the Messenger, were published in Harlem. In D, the phrase and published in Harlem is too remote from the Messenger to modify it effectively. In E, being produces an awkward construction, and the placement of the main clause at the end of the sentence is confusing. Only in C, the best answer, is Published in Harlem followed immediately by the Messenger. Also, C makes it clear that the clause beginning who refers to Randolph.

　　Answer to Question 28

　　In choices A and B, the verb suggest does not agree with its singular subject, rise. In context, the phrase into the coming months in A and D is not idiomatic; in the coming months is preferable. In A, C, and D, the that appearing after but creates a subordinate clause where an independent clause is needed for the new subject, mixed performance. Choice E includes the correct verb form, suggests, eliminates that, and properly employs the future tense, will continue to expand. That this tense is called for is indicated both by the future time to which the coming months refers and by the parallel verb form will proceed in the nonunderlined part of the 161 sentence. Choice E is best.

　　Answer to Question 29

　　Choice A is best. The other choices are unidiomatic or unnecessarily wordy, and the pronoun they, which appears in B, C, and E, has no grammatical referent.

　　Answer to Question 30

　　Besides being wordy, the clauses beginning What was in A and The thing that was in B cause inconsistencies in verb tense: the use of the new technology cannot logically be described by both the present perfect has been and the past was. In B and D, developing the compact disc is not parallel to the use of new technology to revitalize ... performances; in C, the best answer, the noun development is parallel to use. The phrases none the less ... than in D and no less... as in E are unidiomatic; the correct form of expression, no less ... than, appears in C, the best choice.