In China, people have used it for healing since the Qin dynasty.

在中国，自秦朝以来，人们就用它来治疗疾病。

When the final state fell,   the Qin dynasty was born.

当最后的国家灭亡时，秦朝诞生了。

But his empire only lasted 15 years You have a good memory. Do you know what the dynasty was after the Qin dynasty came into end?

但他的帝国只维持了 15 年，你记性真好。 你知道秦朝灭亡后是什么朝代吗？