- Poisonous gases rise to fatal levels so quickly
有毒气体很快就会达到致命的程度
- that an early warning system is essential.
所以即时预警设备是最重要的
- Bats survive by staying close to the skylights,
蝙蝠之所以能生存是因为 它们始终呆在天窗附近
- but venturing deep into the cave is very dangerous indeed.
但是深入洞穴必然极度危险
- 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
- Hydrogen sulphide gas bubbles up from oil deposits in the earth's crust.
硫化氢气体从地壳内的油气储层中溢出
- It mixes with oxygen and the water,
与水中的氧发生化合反应
来自《行星地球 第一季 第四集 Planet Earth S01E04 洞穴》第 282 行