Sometimes, amber can be extracted from open pit mines.
有时候能从开放的矿坑找到琥珀。
Open pit
原声例句
昆虫王国第二季 （原声版）
Space – Verge Science
Some comes from large industrial open pit mines.
有些来自大型工业露天矿。
TED-Ed（视频版）
Much of the time, extracting them requires a method called open pit mining that exposes vast areas of land.
很多时候，提取它们需要一种称为露天采矿的方法，该方法会暴露大片土地。
透视百科科技类
Much of their local waste is disposed in sort of informal ways whether it's behind the house or at a community dump which is essentially sort of an open pit or in some cases directly dumped into the ocean itself.
当地很多的废弃物都用了不正式的处理方式，不管在房子后面还是在社区垃圾场，它本质上是一个露天的坑，或者直接倾倒在海洋中。
英语百科
Open-pit mining
（重定向自Open pit）
Open-pit, open-cast or open cut mining is a surface mining technique of extracting rock or minerals from the earth by their removal from an open pit or borrow.
This form of mining differs from extractive methods that require tunneling into the earth, such as long wall mining. Open-pit mines are used when deposits of commercially useful minerals or rocks are found near the surface; that is, where the overburden (surface material covering the valuable deposit) is relatively thin or the material of interest is structurally unsuitable for tunneling (as would be the case for sand, cinder, and gravel). For minerals that occur deep below the surface—where the overburden is thick or the mineral occurs as veins in hard rock—underground mining methods extract the valued material.