三期必出一期的原理是啥

简介：The smoke and dust raised by the soldiers and horses gradually dispersed, and the officials who saw them off at the city gate also returned to the city one after another. However, there was a second-rank official wearing a scarlet robe and a gray beard who did not move for a long time and remained standing in the same place. He stared steadily at the direction where the prince was going, with worries in his eyes.