We know these exist on Mars because we've seen holes in the roofs, called skylights, openings to the cavern below.

我们知道火星上这些管道的存在，因为我们看到过那些屋顶上的洞，它们被称为天窗，开向底部的洞穴。

Every so often, Julissa and the others stood and pushed their heads out of the limousine’s skylight opening.

时不时地，尤丽莎和其他人站起来， 从豪华轿车的天窗开口探出头来。