Today caves remain the least explored places on Earth. 今天 洞穴仍是地球上 人类最少涉足的地方

6. deep enough to engulf the Empire State Building.
   足以吞没整座帝国大厦
7. This is the biggest cave shaft in the world.
   这是世界上最大的深洞
8. Yet these depths were first explored only two years before man landed on the moon.
   然而人类直到登月前两年 才第一次进入这个深渊
9. Today caves remain the least explored places on Earth.
   今天 洞穴仍是地球上 人类最少涉足的地方
10. However, human beings are seldom the first to reach these black, damp places.
    但是 人类绝非 这个阴暗潮湿地界的第一位到访者
11. Here, live some of the strangest and least-known animals on the planet.
    这里住着一些地球上最奇异 和最鲜为人知的动物
12. This galaxy of little lights is created by thousands of living creatures.
    这“满天星斗”其实是 几千只小动物发出的荧光

来自《行星地球 第一季 第四集 Planet Earth S01E04 洞穴》第 9 行