translation.en: But my very favorite project of all was over 15 years ago, when I was a part of the team that made the very first accurate, three-dimensional map of a subterranean surface.
translation.zh: 但是我最喜欢的一个项目是在 十五年前， 我作为团队的一个成员 绘制了第一张准确的3D下表层地图。