By controlling water, your kidneys stabilize the body's fluid levels.

通过控制水分，你的肾脏 稳定身体的流体水平。

You see, hydration isn’t just about fluid levels; it’s also about what’s contained in those fluids.

你看，水合作用不仅仅与液体水平有关；它还与这些液体中所含的物质有关。

I know how to check the oil, and I know how to check a few different fluid levels in a vehicle.

我知道如何检查机油，我知道如何检查车辆中几种不同的液位。