Answer: The correct answer is : When writing a research paper you should avoid: slang, first or second person, formality, contractions, jargon.
Explanation: When writing this type of work should take into account the impersonality, not make too many subordinate sentences, use more nouns and verbs than adjectives and adverbs, use connectors when necessary, be accurate and precise, avoid metaphors, the text should be clear and understandable.
