一天,三年级的一位学生丢失了一本数学课本,准备到教导处再买一本。他一进门便说:“买一本数学书。”我看了看他,感觉到这学生说话是不礼貌的,必须好好地引导。于是我对他说:“谁要买数学书?”这个学生说:“我要买数学书。” One day, a third-year student lost a math textbook and is ready to buy a copy at the teaching desk. As soon as he entered, he said: “” Buy a math book. “I looked at him and felt that the student was rude to speak and must be well guided. So I said to him: ”Who wants to buy a math book?“ ”This student said:“ I want to buy a math book. ”