阅读下面短文，从各题所给的A、B、C、D四个选项中，选出可以填入空白处的最佳选项。
Do you know One Belt, One Road? We also call it the Modern Silk Road. And Zhang Qian was an early traveler of the Ancient Silk Road. He was probably the first 1 to bring back good information about the central Asian lands to China.
In 138 BC,Han Wudi sent Zhang Qian to the Yue-chi people to ask for their 2 against the Xiongnu who often infringed(侵犯）them.3,on the way to the Western Regions, he was caught by the Xiongnu people. Zhang had to stay with them 4 about 10 years before he got away. When Zhang finaly 5 the Yue-chi in the North India, he was 6 to find that they didn't want to fight against the Xiongnu people.
On 7 return journey, Zhang Qian and his men were 8 again. It was not until 125 BC that they returned to China.9 Zhang didn't finish his job, he learned a lot about the places, people, customs and cultures of the 36 kingdoms(王国）in the Western Regions.
Later Han Wudi sent Zhang to the West again. Zhang's journey to the West helped 10 international trade, especially in silk, between China and the West. That's the Ancient Silk Road.
改写成数值比例尺是