Nobles and knights were obliged to protect those who lived on the manor and provide personal and military service to the king.
The structure of the president's executive office was able to help the role of the office of the President because the office contains multiple and different levels of advisers and staff who are required to help the president in many areas.
1. It enabled the Chinese people to navigate the seas and participate in sea trade.
2. It inspired China to expand its army and conquer more territory.
