Answer:
Teachers of taxation
Step-by-step explanation:
The Mongol Invaders spared teachers of taxation and led to the great expansion of printing all over East Asia.
The Mongol had a persistent thirst for knowledge and were very quick learners, They also helped and contributed to the rise of an educated class in Korea.
The Mongol spared them because they are an asset and use for the development of the country and they also contribute to human existence through the explosion of ideas in sciences, art, and trade which have reformed our history more than any other superpower