Final answer:
China's longest lasting and intense interaction with outsiders was through the Silk Road trade routes, which facilitated the exchange of goods, technologies, and cultural traditions.
Step-by-step explanation:
The longest lasting and intense interaction that China had with outsiders was through the Silk Road trade routes. The Silk Roads connected China with the rest of Asia, the Middle East, and even the Mediterranean, facilitating the exchange of goods, technologies, and cultural traditions.
China's interactions with outsiders through the Silk Road included trade with nomadic peoples, such as the Xiongnu and Yuezhi, as well as cultural exchanges with countries like Korea and Japan.
China's interaction with outsiders, particularly through the Silk Road, played a crucial role in the spread of Buddhism and other religions.
Learn more about Silk Road trade routes