Take mathematics for example. Many people are under the impressions that advanced mathematical study in university is so theoretical that it does not have any practical value. However, the truth is that, ours is an age in which all areas of science are permeated more and more by methods and approaches derived from theoretical knowledge in mathematics. Even marketing, once believed to be just an art of persuading people to buy, is now becoming a scientific subject based on statistical studies of market data, which requires profound mathematical knowledge.

　　2. Practical trainings are based on theoretical knowledge. / Practical trainings and theoretical studies are interrelated.

　　a) Some professions require that people have solid understanding in theoretical knowledge before going into practice in those professions.