根据所给汉语或英文首字母写出短文中所缺英语单词。

    Confucius, a pioneer in the field of (教育). He was born in the year 551 B. C. He was a great thinker who had many wise ideas about human nature and behavior. His main ideas are about kindness and good manners. He was also a famous philosopher whose wise sayings have i many people in d countries. For example, one of his famous sayings, "He who learns but does not think is lost; he who thinks but does not learn is in d", tells us the (重要性) of learning and thinking.