The participle of "give" is "given," not "gave." Since the verb "took" is in past tense, "having already given" is the appropriate selection here. A comma is necessary after "Gordon" to indicate the modifying appositive phrase.

This sentence contains 3 verb errors:

1. The tense of the first "is" is incorrect.
2. The number of the first "is" is incorrect.
3. The number of the second "is" is incorrect.

The word "once" and context indicates that the "things" were expensive in the past. They cannot be both expensive and cheap at this very moment, which is what the present tense indicates. Furthermore, "is" is singular, when "things" is plural, so the number needs to be changed from singular to plural in order for these words to agree; the correct choice here would be "were" (was is singular). Lastly, the word "is," as stated before, is singular when it needs to be plural in order to properly modify the word "things." The correct word would be "are." The correct choice is, "things that were once expensive are now cheap."

Subjunctive constructions do not need “should.” “Indicates for” is an incorrect idiomatic usage. “These reports completion” requires “reports” to be in the possessive; regardless, it is awkwardly worded.

After the auxiliary forms of the verb "to be," we use subject forms of pronouns, except after the infinitive where we use the object form. “Divulge with” is unidiomatic.

This sentence contains a verb error. The word "thinked" is not a form of the word "think." The perfect past form, which is necessary here, is "thought." Note that "thinks" would be incorrect because it would mark an inappropriate tense shift (the rest of the sentence is in the past, while "think" is present tense). The correct choice is, "He liked history books because he thought that."

The use of "marching" makes the sentence not have a verb, as the participle form always needs some form of the verb "to be" used immediately before it to make it a complete verb. (For example, it's not grammatically correct to say "The fish swimming across the lake." Anyone who heard this might ask, "The fish swimming across the lake did what?" since "swimming" is a participle—a verb acting like an adjective. Instead, the correct way to say this would be, "The fish was swimming across the lake," or, alternatively, use a different verb form altogether, such as "The fish swam across the lake." To correct the problem's sentence, either the participle "marching" needs to be preceded by some form of the verb "to be," or it should be changed to some other form than the present participle to avoid functioning as an adjective and instead clearly function as the sentence's verb. The only answer choice that uses either of these options is "The battalion marches towards the battlefield on their way to the conflict."

The placement of the adverb "initially" is incorrect in this sentence, as it places the modifier in the midst of the complex verb used in the second part of the sentence. It needs to be placed directly before the full verb construction. The only answer choice which does this is "than the one that initially had been given by the building’s architect."

In this sentence, both "extreme" and "specified" are incorrectly used, and need to take on their proper forms. The adjective "extreme" is used instead of the adverbial form, and the word "specified" is used where the related word "specific" is more appropriate. Therefore, as the only answer choice that correctly makes these changes, the correct answer is "allocating funds in extremely specific manners."

"Unique" means one of a kind, and nothing can be more "one of a kind" than anything else. The phrase "by far the most unique" needs to be taken out of the sentence and rearranged to properly use "unique" in the sentence. The only answer choice which correctly uses "unique" is "she was unique among all of the students at the academy."

The use of the verb "baffling" in this sentence is incorrect, as the "detectives" are being affected by the "series of murders." This means that the verb, which in this case is used as a participle, should be placed into a past tense form. Only one choice, "completely baffled by the series of murders," correctly makes this change.