They plumb the depths down to 600 meters, in temperatures to one degree centigrade, and this is why you see them on the surface — it's so cold down there.
它们垂直下降可达600米，那里的温度仅1摄氏度，这也是为什么会看到它们在海面的原因，那下面太冷了。
3
The world's a pretty low down place to have a thing like you prowling around in it, but it ain't so plumb low down, I reckon, as to let you put a hole in me.