And I was searching for hints of the existence of cave systems through satellite images, and finally we identified an area of collapses of the surface -- so, big boulders, rock piles -- and that means that there was a void below.
通过卫星图像， 我寻找洞穴系统 存在的迹象， 最终我发现一个区域有地表坍塌的现象—— 也就是说，大块的、成堆的岩石—— 这表明，底下是空的。