Correct Answer: D

Rationale: The correct answer is D, 'Exclamation mark.' Exclamation marks are used to express strong emotions such as excitement, surprise, or urgency. They indicate a heightened level of emotion in a sentence. Periods (A) are used to indicate the end of a statement, commas (B) are used to separate elements in a sentence, and question marks (C) are used to indicate questions or uncertainty. In this context, the use of an exclamation mark is the most appropriate choice to convey a strong feeling or emotion.

Correct Answer: A

Rationale: In the sentence provided, the words that function as nouns are 'Robert,' 'sources,' 'project,' 'databases,' and 'research.' These words are all objects or concepts that can be referenced or identified in a sentence as nouns. Choice B includes adjectives ('final,' 'academic') which describe other nouns rather than being nouns themselves. Choice C includes a pronoun ('he') which is not a noun. Choice D lacks the noun 'Robert' which is a subject in the sentence.

Correct Answer: C

Rationale: The sentence is a direct question as the speaker is asking if the person will send a postcard from Germany. Therefore, the correct punctuation mark to use at the end of a question is a question mark. An exclamation mark (Choice D) is used to convey strong emotion or surprise, which is not the case here. A period (Choice A) is used for declarative statements. A colon (Choice B) is used to introduce a list or explanation, which is not needed in this context.

Correct Answer: A

Rationale: Choice A, 'I disagree with the argument about contract workers having greater freedom,' is the correct answer. This sentence rephrases the original statement in a more formal and respectful tone, which is suitable for formal writing. Choice B is too direct and lacks formality. Choice C does not address the argument directly and poses a question instead of providing a formal statement. Choice D is dismissive and does not offer a formal rewrite of the original sentence.

Correct Answer: D

Rationale: The correct answer is D. This sentence uses the second person point of view by directly addressing the reader or listener with the phrase 'Be sure to.' It is instructing or advising someone on what action to take, making it a clear example of second person point of view. Choices A, B, and C all use first person (I) or third person (she, Pluto), which do not involve direct interaction with the reader or listener, unlike the second person point of view present in choice D.