In most cases, extracting oil involves chopping down the forest that blankets the region, draining the boggy ground, stripping off the topsoil and literally digging up the oily sand below.
In most cases, extracting oil involves chopping down the forest that blankets the region, draining the boggy ground, stripping off the topsoil and literally digging up the oily sand below.
在大多数情况下，要从油沙中提炼出石油需要先把覆盖该地区的森林砍掉，排干地面的水分，去掉表层土然后当然就是把地下的油沙挖出来。