"Chatting online" is a gerund phrase, while "video games" is a noun. In an "either . . . or" phrase, however, both elements of the phrase need to be of the same kind of word. "Either chatting online or playing video games might appear" is the only answer choice that uses an appropriate parallel structure.

Parallelism is the key here—all the descriptions should be in the same format, which is a single word adjective. The correct answer also makes the sentence more concise and more fluid, which is another benefit of having parallel sentence structure and another way to tell which answer choice is best.

As it is written, the sentence uses parallelism incorrectly because the two things the governor supports are different word forms - "abolishing residential taxes" is a gerund phrase, and "to create new state parks" is an infinitive phrase. Changing the infinitive phrase to a gerund phrase makes the sentence sound more fluid.

The sentence must have parallel structure. The quantifier “some” should appear before each fruit, or it should be left out completely. The verb “to decide” must be followed by an infinitive verb (“to buy”).

The sentence suffers from a form of faulty parallelism, in which the third item in a parallel series doesn't share the same grammatical form as the other items in the series. The third item, "he desired to win," is stated as a clause, while the other two items, "agility" and "grace," are nouns. The easiest way to fix this problem is simply to change "he desired" to "a desire."

The list that makes up the underlined portion of the sentence does not correctly employ parallel structure, making it actually describe wildly different things, like the act of "managing" with the topic of "computer science." The three elements in the list need to have the same structure, making "computer science, leadership techniques, and account management," the correct answer choice, as here, all of the elements are presented as nouns.

Elements in a list must have the same grammatical structure in order to be parallel. In this case, the first two items in the list are gerunds: "practicing" and "eating." The third item in the list, however, is a noun: "classes." To correct the sentence's error, the noun "classes" should be replaced by a gerund, and the only answer choice that does this without introducing other errors is "practicing French, eating regional food, and taking classes during their trip abroad."

This sentence's error is one of parallel structure: all of the items in the sentence's list need to be written in the same form. As it is written, the sentence's list includes one present progressive verb ("taking") and two past-tense verbs ("unfolded" and "curled up"). All of these items need to match, so we either need to change "unfolded" and "curled up" to "unfolding" and "curling up," or "taking" to "took." "He was seen took" is grammatically incorrect; we need the present progressive verb, "taking." So, we need to change "unfolded" and "curled up" to "unfolding" and "curling up," making the correct answer "What do you make of the fact that he was seen taking off his shoes, unfolding a blanket, and curling up for a nap in one of the café's booths?"

Let's take a look at the parts from which this this sentence is composed: we have "No one," a subject, "has ever sailed," a verb, "through the treacherous waters," a prepositional phrase, and then "was able to tell anyone about it afterward," a predicate. This sentence has too many verbs. While there are numerous ways to make this sentence grammatically correct, one way is to make the underlined portion into a subject; that way, the sentence would consist of a subject, followed by a prepositional phrase describing that subject, followed by a predicate. The answer choice "No one who has ever sailed" adds in the subordinate conjunction "who" to make what was a verb ("has ever sailed") into a subordinate clause ("who has ever sailed"), making "No one who has ever sailed through the treacherous waters" one big subject and the sentence grammatically correct. While the other answer choices "No one who will sail" each function as a subject, it introduces the future verb tense that doesn't match the past-tense verb "was able" that appears later in the sentence.

This sentence's error is one of parallel structure. The first two items in its list, "Public education" and "health care," are nouns, but the third item, "the constructing of new roadways," begins with a gerund. All of the items in a list should be formatted in the same way. There are numerous ways in which we could change the sentence so that each of its items take on the same grammatical form, and several answer choices correctly fix this issue; only "Public education, health care, and constructing new roadways are all areas," which changes the gerund "constructing" to a present progressive verb by omitting the definite article "the," does not do this.

All but one of the answer choices that fix the parallel structure of the list introduce new errors. "Public education, health care, and new roadway construction is all areas" incorrectly uses the singular verb "is" to refer to the plural compound subject, so it is incorrect. "All areas are public education, health care, and new roadway construction" convolutes the sentence's word order and makes it confusing by making it seem as if "all areas"—all of the areas in total, not just the ones "that we desperately need to fund"—are the three listed. Only "Public education, health care, and new roadway construction are all areas" fixes the sentence's error without introducing new mistakes, making it the correct answer and the corrected sentence "Public education, health care, and new roadway construction are all areas that we desperately need to fund."