在我国工程监理分为( )。
A．策划监理和施工监理B．策划监理和设备监理C．运营监理和施工监理D．施工监理和设备监理
参考答案：D
全棉的漂白平纹机织物，250克/平方米
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 ？
