The teacher seemed to be explaining why they had originally given Jiang Yue fifty coins only to reduce it to forty-nine, leaving a line of text written in red ink beneath.
Yet, that line contained only four characters: "Excessively sharp."
In other words, the content of her essay was so sharp that the teacher, after much consideration, decided it was best to deduct a point.
Jiang Yue didn't mind, as grading Chinese papers wasn't like grading math papers, which have standard answers, especially Chinese compositions, which have no standard answers.