"Not only...but also" is a correlative conjunction pair used to add emphasis. When "not only" begins a sentence, inversion occurs: "Not only was the Erie Canal..." This structure correctly connects two positive qualities of the canal.

"That Betsy Ross" introduces a noun clause serving as the subject of "is widely believed." The conjunction "that" introduces a fact or belief as a subject clause. "When" and "Whether" imply doubt or time, which do not fit the context.

"Not only...but also" is the correct correlative conjunction pair in English. The structure must always be completed with "but also" to maintain parallel construction and proper grammatical balance between the two options.

"The first" is a noun phrase that correctly serves as a pre-modifier for "steam locomotive." The definite article "the" is used with superlatives and ordinal numbers. Options B, C, and D create grammatically incorrect sentence structures.

"Analyze" is the correct base form of the verb agreeing with the plural subject "Geologists." A plural subject requires a base form verb in simple present. "Analyzes" is for singular third-person subjects. "Analyzing" requires an auxiliary verb.

"Meaning" is a present participle used as an adjective modifying the word "nebrathka." Participial phrases provide additional information about a noun. "To mean" implies purpose, "it means" creates a run-on sentence, and "by meaning" is awkward.

"But" is the correct conjunction showing contrast. The sentence contrasts where fat is NOT digested (stomach) with where it IS digested (small intestine). This "not...but" construction is a standard English pattern for expressing contrast.

"In the" correctly introduces a prepositional phrase of time: "In the early 1960s." Time expressions require the preposition "in" followed by the definite article "the" before decade references. Options A, B, and D create grammatically incomplete or incorrect structures.

"So" is the correct conjunction here because it introduces a result or consequence. The Earth's gravitational attraction (cause) results in bodies falling toward the center (effect). "So" correctly links cause and effect between the two clauses.

"Are two plates" uses subject-verb inversion after an introductory prepositional phrase "At the far end." When a sentence begins with a location phrase, the verb precedes the subject. "There" is unnecessary when the location is already stated at the beginning.

"Compared" is the past participle used in a reduced passive clause meaning "when compared." This participial phrase modifies how relative humidity is measured. "Compared with" is a standard English phrase for making comparisons.

"If they are to be" introduces a conditional clause meaning "in order to be." This expresses a condition or requirement. The fibers must be spun into thread as a necessary step before they can be woven into fabric.

"One of the" is the correct phrase before a superlative adjective ("largest") with a plural noun ("landholders"). This construction means she was among the group of largest landholders. "What the" and "who the" are used for different sentence structures.

"During" is the correct preposition for a time period or era. "During the early Permian period" means throughout or at some point within that period. "When" introduces a clause with a verb, but "the early Permian period" is a noun phrase, not a clause.

"Where apricots can" introduces a relative clause modifying "areas." The relative adverb "where" refers to places. The clause must have normal subject-verb order: "where apricots can be grown." Option D has incorrect inverted word order in the relative clause.

The error is at (B): "begin" should be "to be." The verb "consider" followed by an object and complement requires "to be" or an adjective, not "begin." The correct form is: "consider computer literacy to be a necessary addition."

The error is at (A): "trusty" should be "trust." The sentence lists abstract nouns in parallel: "Friendship, stability, and trust." "Trusty" is an adjective meaning reliable, which breaks the parallel noun structure of the series.

The error is at (D): "information's" should be "information." "Information" is an uncountable noun and does not take a possessive apostrophe or plural form. The correct form is simply "obtain information on a particular topic."

The error is at (B): "too" should be "so." The correct structure for expressing result is "so...that," not "too...that." "Too" implies excess without a result clause. The correct form is: "Rubber can be made so elastic that it will stretch..."

"The United States exports" provides the correct subject and verb for the subordinate clause introduced by "Although." The main clause already has "it" as the subject referring to the United States, so the subordinate clause needs its own complete subject-verb pair.

"The" is the correct definite article before "chief material." The sentence is a simple statement with "the chief material" as the subject. Adding "it was," "that," or "there was" would create grammatically incorrect or unnecessarily complex structures.

"Require" is the correct present tense verb in a relative clause modifying "calcium." The clause "their bodies require" means the calcium that their bodies need. Present simple is used for general truths and ongoing needs.

"No" is the correct negative determiner modifying the noun "social cause." The sentence means that no other social cause aroused more enthusiasm than this one. "Nothing" and "None" are pronouns, while "Not" is an adverb — neither can directly modify a noun.

"The early gold prospector often lived" is a complete, grammatically correct sentence with a clear subject and past tense verb. Option A is a fragment without a main clause, Option C requires a "but also" clause to complete it, and Option D has no finite verb.

The error is at (D): "annual" should be "annually." An adverb is needed to modify the verb "raised." "Annual" is an adjective. The correct form is: "are raised annually in greenhouses."