when cavers dug through several metres of loose rock 洞穴专家们在松散的岩层中 挖出了一条几十米深的通道
The source of these toxic fumes lies several miles below. 这些毒气的源头位于地下几英里处
The salamander might not encounter food for several months, 童态河溪螈可能 已有几个月没有吃东西了