subsurface structure

例句：

1. 1. The geologist used a seismic survey to map the subsurface structure of the region.
   地质学家使用地震调查来绘制该地区的地下结构。
2. 2.The research team discovered that the subsurface structure beneath the city was significantly different from what they had previously thought.
   研究小组发现，城市下方的地下结构与他们之前认为的有很大不同。
3. 3. The engineer proposed a new design to improve the stability of the subsurface structure.
   工程师提出了一种新的设计，以提高地下结构的稳定。