The underlined part of this sentence sounds awkward because its structure does not match the structure of the two previous phrases in the list of what Tom will do. According to the sentence, Tom will “play basketball” and “practice piano”. The third item in the list of what Tom will do should also be an active verb phrase. So, “watch a movie with his friends” is the best answer.

This sentence uses the format of “not only X, but also Y”. According to the narrator, Clara had done two things: “upended the flowerpots” and “chewed up” the couch cushions. We should change the underlined part of the sentence into the active voice, so that it matches the structure of the previous phrase, “upended the flowerpots”. The best and most concise way to create parallel structure would be to say that Clara “had not only upended the flowerpots but also chewed up the couch cushions.”

In this sentence, we have a list of three things. The narrator says that she had “talked to [her] teacher” and “gone to the library”. The third item in the list, “when I had looked on the Internet”, doesn't match the structure of the first two items. We should shorten the underlined part of the sentence by changing it to a phrase that begins with the past participle of a verb, so that it matches the structure of the first two phrases in the list. Simply writing “looked on the Internet” is the best answer.

To correct this sentence, we have to think about how to create parallel structure and about what the speaker wants to express. In the way the sentence is currently written, it sounds like the narrator's mother doesn't know whether she will “rent a car” or rent a taxi – the word “rent” being implied in the second phrase. However, we actually say “rent a car” and “take a taxi”. The best way to rewrite the sentence is, “She hasn't decided whether she should rent a car there or take a taxi. The other choices either do not create parallel structure or contain redundant elements.

According to this sentence, the amount of material that ends up in landfills illustrates two ideas: “that people don't care enough about recycling” and “our current social and political attitude toward the environment needs to be changed.” The second phrase sounds awkward, because it doesn't match the structure of the first phrase. We should add a “that” to the beginning of the second phrase to make it echo the structure of the first phrase. So, “that our current social and political attitude toward the environment needs to be changed” is the best answer.

This sentence is correct as it is. The sentence includes a list with three items: the artist's “great technical skill”, his “attentive observation”, and his “remarkable sensitivity”. Each of these items has the same kind of structure: they are all noun phrases that each begin with modifying adjectives. The list already shows good parallel structure, so nothing needs to be changed in the underlined part.

When listing a set of actions, parallel structure must be used.  This means that the verbs mush be in the same tense.  In the sentence above, there are two verbs (speaking and riding) in the same tense, but went is in the past tense.  Went must be changed to going in order for parallel structure to be achieved.

This is a parallel structure error. There are three items in a list (athleticism, intelligence, and the underlined portion). The first two are listed as nouns that describe Alyce's positive traits. The last one, as written, introduces a verb tense. We want the underlined portion to be in the same form as the first two words, so we need a simple descriptive noun (kindness).

This is another (more subtle) parallel structure error. The second verb in the sentence needs to be in the same form (past tense) as the first and refer directly to the subject, the final exam itself, not the students. The only answer choice that does this correctly is "and required critical thinking." The choice "and they required critical thinking" may look similar but it actually changes the subject of the sentence and/or introduces an agreement error in number with the original subject.

This is a parallel structure error. In the first phrase the musician is praised for her technique, so in the second phrase she also needs to be praised for her expressive interpretation (not in it).