In the figure above, two searchlights S₁ and S₂ are located 10,000 feet apart, each covers an area of radius 10,000 feet, and each is located 8,000 feet from the railroad track. To the nearest 1,000 feet, what is the total length x of track spanned by the searchlights ？

执法必严，直接（），是物业区域清洁管理的原则之一。

A.检查

B.考核

C.管理

D.监督