Do you know the Silk Road? It is the of different roads that connected Europe, Africa and Asia long ago. People arrived at these different places along these in the old days. Zhang Qian was a famous traveler of the Silk Road. He was probably the first person to back good information about the central Asian lands to China.
In 138 BC, Emperor Wu of Han sent Zhang Qian to Yue-chi to for help to fight against Xiongnu. But on his way there, the Xiongnu people caught him. Zhang had to stay with them about 10 years before he got away. When Zhang finally reached Yue-chi, he was to find that the people there didn't want to fight against Xiongnu. On his journey back to China, Zhang Qian found a lot of good things and brought back.
Later, Emperor Wu of Han sent Zhang to the West 。Zhang's journey to the West helped develop the international(国际的) business, especially in silk between China the West. That's the Ancient Silk Road.
Now the old Silk Road are still used, they are crossed by trains, not by camels or horses. People along the road still do business with each other. Now it is called New Silk Road. Another saying is One Belt, One Road(一带一路).