Correct Answer: C

Rationale: The correct word to use in this sentence is 'taking' to show the continuous aspect of the action. The sentence should read: 'Having taking one pill at bedtime, the patient was able to sleep for eight hours.' 'Taking' is the present participle form of the verb 'take,' which is appropriate in this context to indicate the ongoing action of taking a pill at bedtime. Choice A, 'took,' is incorrect as it is the simple past tense, not suitable for this sentence's structure. Choice B, 'take,' is the base form of the verb, which does not fit the sentence's requirement for a participle. Choice D, 'taken,' is the past participle form, which is also unsuitable for showing the ongoing action required in this context.

Correct Answer: C

Rationale: The phrase 'and new tires' is misplaced in the sentence as it disrupts the flow of information. It introduces unnecessary detail that does not directly contribute to the main point of the sentence, which is identifying the ownership of the car. Choices A, B, and D are all essential parts of the sentence that help convey the location of the car and its ownership, making them correctly placed within the sentence.

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.

Correct Answer: B

Rationale: The correct sentence should be: 'Because of a major accident on the freeway, the emergency room was overcrowded.' A comma is needed after 'freeway' to separate the introductory dependent clause from the independent clause that follows. Choice A (Period) is incorrect as it would create two separate sentences. Choice C (Exclamation point) is incorrect as there is no exclamation in the sentence. Choice D (Semicolon) is incorrect as it is used to separate closely related independent clauses.

Correct Answer: A

Rationale: The correct word to use in this sentence is 'volunteered' as it indicates an action that Cathy did in the past. The sentence suggests that Cathy was engaging in volunteering at the hospital for the first time, so the past tense form 'volunteered' is the most appropriate choice. Choice B ('volunteering') is incorrect because it is the present participle form and does not fit the past tense context of the sentence. Choice C ('was volunteered') is passive voice and implies that someone else made Cathy volunteer, which is not the intended meaning. Choice D ('volunteer') is incorrect as it is the base form of the verb and does not match the past tense requirement of the sentence.