Question

live at a depth of more than3100 feet 为什么live后面用的是at

Answer 1

at a depth of.可看成固定搭配

Grass and clover seed should be sown at a depth of 12 - 20 mm.

禾木科草和三叶草播种深度应为 12-20 毫米.来自辞典例句

Water was found at a depth of 30 ft.在30英尺深处找到了水.