In fact, on a good day, we might have four or five human beings at the average depth of the Earth -- maybe four or five human beings out of whatever billions we've got going.
事实上，在一个风和日丽的日子，我们可能有四、五个人 在地球的平均深度上—— 也许是几十亿人中的四、五个人开始行动了。