Correct Answer: C

Rationale: In this sentence, we are looking for a pronoun that refers to more than one person. The children and 'them' performed a skit for the elderly patients. 'Them' is the correct pronoun to use in this context to indicate a group of people, which is the plural form of the pronoun. Choice A, 'he,' is singular and would not match the plural subject. Choice B, 'me,' is an object pronoun and does not fit the subject position. Choice D, 'her,' is singular and does not agree with the plural subject 'children and them.' Therefore, the correct answer is 'C: them.'

Correct Answer: B

Rationale: The correct punctuation needed in the sentence is a comma. A comma should be placed after 'festivities' to separate the two independent clauses in the sentence: 'In addition to the hospital's regularly scheduled festivities' and 'the custodians celebrate with a party of their own.' The comma helps in improving the clarity and structure of the sentence by indicating a pause between the clauses. Choice A, 'Period,' is incorrect because a period would create two separate sentences rather than connecting the related clauses. Choice C, 'Apostrophe,' is incorrect as there is no need for an apostrophe in this context. Choice D, 'Semicolon,' is incorrect because a semicolon is used to join closely related independent clauses, which is not the case in the given sentence.

Correct Answer: B

Rationale: The word 'whose' in the sentence should be 'whose.' 'Whose' is the correct possessive form used to indicate that the diploma belongs to the doctor. 'Who's' is a contraction for 'who is' or 'who has,' which does not make sense in this context. The other words in the sentence - 'That,' 'hung,' and 'partition' are all used correctly in the sentence.

Correct Answer: D

Rationale: The phrase 'in the auditorium' is misplaced in the sentence because it suggests that the dangers of drugs and alcohol were in the auditorium, which is not the intended meaning. It would make more sense for this phrase to come immediately after 'he informed us' to indicate where the presentation took place. Choices A, B, and C are all correctly placed within the sentence, providing necessary information about the context and topic of the presentation.

Correct Answer: B

Rationale: In the given sentence, the word 'once' is used incorrectly. The original sentence implies that the professor was an intern in the hospital at a specific time in the past, not just once. The word 'formerly' would imply that the professor used to be an intern but is no longer. Therefore, 'once' is the incorrect word choice in this context. The other options ('professor,' 'intern,' 'hospital') are all used correctly in the sentence.