英语听力：自然百科 探索世界奥秘之Genghis Khan(成吉思汗)Unit09（在线收听）

Temujin granted his blood brother his final wish and broke his back.

The defeat and death of Jamuqa led to a sight never before seen in the history of Mongolia: the recognition of one man as the leader of all the Mongol tribes. In the Mongol world, there had never been such a figure. And in 1206, a new title was created to honor him: Universal King, ruler of all men, Genghis Khan.

"But my destiny, the destiny of the great Mongol people was still unfulfilled."

Genghis Khan had forged a nation. But now, he faced a new and more potent threat: China. He knew the Chinese would not tolerate such a powerful leader as him on their border. So he took the fight to them. In a campaign that was to last six years, he led his army of 50,000 Mongols on one of the most audacious military actions in history. He crossed the Gobi Desert and invaded Northern China. On hearing that the Mongol army was approaching, the emperor of North China sent this message: "Our empire is as vast as the sea, yours is but a handful of sand. How can we fear you?" The Chinese had spent centuries perfecting their defenses, but Genghis Khan solved the problem posed by China's biggest border defense, the Great Wall, by one simple expedient: they went around it. The Chinese were the richest and most civilized people in the East. But they also knew how to fight a dirty war. Iron spikes, like medieval minefields, were bedded in the path of the oncoming Mongol armies.

grant: agree

potent: strong, influential

perfect: refine, improve

expedient: means, method, scheme, plan, move, tactic