密西西比河的水位已经比正常水位低6.5英尺。
There wasn enough difference between the height of the ground level and the water level.地面高度与水位没什么明显的区别。
When they dropped a stone into a wide tube, the water level raised in a connected narrow tube.当他们把一块石头扔进一个粗试管时,相连的一个细试管里的水位上升了。