The phosphorus at the bottom of the ocean has to somehow make its way back to the surface, to complete the cycle, to begin the cycle all over again.
海底的磷必须找到某种方式回到表面，以完成这个循环，从而重新开始这个循环。
2
Hydrothermal vents are cracks in the Earth's surface that occur, the ones we are talking about here are found deep at the bottom of the ocean.
深海热泉是地球表面出现的裂缝，我们在这里提到的裂缝是在海底深处发现的。
3
If the glass were kept hot enough, it would flow over the molten tin until the top surface was also flat, horizontal and perfectly parallel to the bottomsurface.