Correct Answer: A

Rationale: In this sentence, 'she' is the correct word to use. The sentence implies that someone (a female) helped the speaker finish their degree. The pronoun 'she' is used to refer to a female person. Without this person's help, the speaker would not have completed their degree. Therefore, the correct word for the blank is 'she.' Choices B, C, and D are incorrect because they do not match the context of the sentence, which specifically mentions the need for help from a female individual.

Correct Answer: A

Rationale: The phrase 'of workers' is misplaced in the sentence because the preposition 'of' is unnecessary and disrupts the flow of the sentence. It creates redundancy as 'a number of workers' can be simplified to 'workers.' Removing this unnecessary prepositional phrase would make the sentence clearer and more concise. Choice B 'from my car window' is correctly placed as it provides context on where the observation was made. Choice C 'who were repairing the road' and Choice D 'alongside the mall' are essential parts of the sentence providing details about the workers' activity and location, respectively.

Correct Answer: B

Rationale: The correct punctuation needed in the given sentence is a comma after 'class.' This comma is necessary to separate the two independent clauses 'Do not be afraid to ask questions in his class' and 'he is very approachable and explains things well.' Commas are used to separate independent clauses when they are joined by a coordinating conjunction like 'and.' Choice A, 'Hyphen,' is incorrect as a hyphen is not needed to connect any words in the sentence. Choice C, 'Apostrophe,' is incorrect as there is no possession or contraction being indicated in the sentence that requires an apostrophe. Choice D, 'Semicolon,' is incorrect as a semicolon is not used to join two independent clauses in this context; a comma followed by a coordinating conjunction is more appropriate.

Correct Answer: A

Rationale: In this sentence, 'she' is the correct word to use. The sentence implies that someone (a female) helped the speaker finish their degree. The pronoun 'she' is used to refer to a female person. Without this person's help, the speaker would not have completed their degree. Therefore, the correct word for the blank is 'she.' Choices B, C, and D are incorrect because they do not match the context of the sentence, which specifically mentions the need for help from a female individual.

Correct Answer: B

Rationale: The correct answer is 'itself.' The sentence is referring to the centrifuge, which is an object, not a person. Therefore, the word 'itself' is used to indicate that the centrifuge cannot run on its own; it requires constant attention. Choices A, C, and D are incorrect because they refer to a person or people, which is not suitable in the context of the sentence.