2. Three quatrains of Huaqing Palace (I): Mount Li, with lush trees and flowers, stands in the middle like a beautiful group. The magnificent palaces at the top of the mountain suddenly opened slowly one after another. Outside the palace, a messenger galloped on a post horse, raising clouds of red dust behind him; In the palace, the princess smiled. "Biography of Yang Guifei in the New Tang Dynasty": "My concubine loves litchi and wants to be born, so she rode it for thousands of miles, and her taste has not changed. She has arrived in the capital." Judging from this poem, horses were the means of transportation used in the Tang Dynasty, and the transportation facilities were post stations. People-to-people communication is mainly carried by special envoys riding post horses station by station.
3. "Send Yuan to Twenty Shores Xi": This is a poem to send friends to the northwest frontier. Anxi, the abbreviation of Anxi Duhu, was established by the central government of the Tang Dynasty to govern the western regions, located in Qiuci City (now Kuqa, Xinjiang). The friend named Yuan went to Anxi on the orders of the imperial court. In the Tang Dynasty, most people who traveled westward from Chang 'an saw them off in Weicheng. Since the Han Dynasty, Yangguan has been the gateway from the mainland to the western regions. The national strength of the Tang Dynasty was strong, and there were frequent exchanges between the mainland and the western regions. Joining the army or going to Yangguan is a desirable feat in the eyes of the prosperous Tang people. But at that time, the western part of Yangguan was still poor and barren, and the scenery was very different from that of the mainland. Although it is a feat, my friend's "going out to the west" can't help but go through the long March and prepare for the hardships and loneliness of going alone. In ancient times, land transportation was inconvenient, and it was easy to meet each other when leaving, so farewell became a form of people expressing deep affection and friendship, and also became the theme of poets competing to sing.
4. "Send Minister Chao Jian back to Japan": Chao Jian (Heng), that is, Abe Zhongmalu, went to Tang with the Tang envoy. He was an official in the Tang Dynasty and was highly valued by Emperor Xuanzong of the Tang Dynasty. He has deep contacts with Li Bai and Wang Wei. In 753, on his way back to China, he was stopped by a storm, returned to the Tang Dynasty and died in Chang 'an. Although the great progress of shipbuilding and navigation technology in the Tang Dynasty (such as larger hull and stronger structure, and the wide application of compass, star guide, nautical chart and monsoon navigation AIDS), navigation activities entered a prosperous period, but the waves at sea still blocked Chao Jian's way back to China.