Background: Deep in the bowels of Cheyenne Mountain is a city-like military complex that once served as North American Aerospace Defense Command (NORAD) 's center.
背景材料：在夏延山的深处像一座城市一样的军事综合隧道，一度作为北美防空司令部(NORAD)的中心。
2
Wuyi Mountain has sound infrastructure facilities, serving as the key traffic center for North Fujian Province.
武夷山交通等基础设施完善，是闽北的重要交通中心。
3
Naughty finally came to the center of the island, where there is a golden mountain.