Correct Answer: D

Rationale: The teacher should advise the student that 'ain't' is a colloquial expression, and while it may be suitable in informal or conversational settings, it is not standard in academic writing. Using colloquialisms like 'ain't' in formal research papers can diminish the professionalism and clarity of the writing. Choice A is incorrect as the presence of a word in the dictionary does not solely determine its appropriateness in formal writing. Choice B is incorrect because the student's academic level does not justify the use of non-standard English. Choice C is incorrect as it focuses on the perceived uneducated sound of 'ain't' rather than its appropriateness in formal writing, which is the key concern for the research paper in question.

Correct Answer: A

Rationale: The correct answer is A: '-ize'. When '-ize' is added to 'money', it forms the word 'monetize'. 'Monetize' means to turn something into money or profit. Therefore, the sentence should read: 'Entrepreneurs monetize their ideas,' which accurately conveys the intended meaning of using ideas to generate profit. Choice B, '-ical', is incorrect as it does not create a verb from 'money'. Choices C and D, '-en' and '-ful', are also incorrect as they do not form a verb related to 'money' in the context of the sentence.

Correct Answer: A

Rationale: The topic sentence sets the stage for the discussion that follows. Choice A, 'The Civil War was a war that was not easily won, but hard fought,' is the most appropriate as it introduces the theme of the challenges faced during the Civil War and the determination required for victory. Choice B, 'The Civil War ended in 1865,' is a factual statement but does not lead into the paragraph content. Choice C, 'Jefferson Davis was the President of the Confederate States,' introduces a different historical figure not central to the paragraph. Choice D, 'Many countries have had civil wars,' is a broad statement not related to the specific context of the Civil War in the United States.

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: D

Rationale: In the sentence, 'The realtor showed her and me a house on Wednesday afternoon,' the pronouns 'her' and 'me' are used as objects of the verb 'showed.' When choosing pronouns to fill in the blanks, it is important to use objective pronouns to maintain correct grammar and sentence structure. Choice A ('She, I') and Choice B ('She, me') are incorrect as 'I' and 'she' are subjective pronouns, not objective pronouns needed as objects in this sentence. Choice C ('Me, her') is also incorrect as the order and usage of pronouns are reversed from the correct form in the sentence.