英语听力：自然百科 圣河之旅 The Nile尼罗河—18（在线收听）

 Rising up alongside confluence is the Khartoum, the capital of Sudan. I'd arrived in the city on a Friday. Islamic mystics known as Sufi were gathering at the edge of the city to perform a weekly sunset ritual. It harks back to the earliest days of Islam on the Nile. These are whirling dervishes of Sudan. The journalist Ismal Kushkush was at hand to help me understand this magical. It's fairly chaotic spectacle. What are they doing? It's called zikr or rememberance. It's a way to purify the heart by reciting the certain chants, certain poetry. To purify them, purifying the heart, does that mean effectly clensing the body of evil. Absolutely. Through remembering the Gods, through these recitations, that heart is purified from any evil. It becomes closer and in oneness with the Lord. As the Sufi spin to rhythmic chants of crowd, then enter into a kind of trance. Their meditative state is intensified by the  overwhelming fragrance of frankincense. That's beautiful, beautiful smell.