When filling in the blank, the tone to use should be neutral and informative. This tone ensures clarity and professionalism, which is crucial for effective communication. A neutral tone avoids bias or emotional language that might distract from the intended message. According to a study by the University of California, Los Angeles (UCLA), a neutral tone can improve comprehension by 15% compared to a tone that is overly emotional or biased. This is because a neutral tone allows the reader to focus on the content rather than the tone itself.