Then steam power entered the scene, putting the whole future of waterpower in doubt.
随后，蒸汽动力登上了历史舞台，让整个水力发电的前景一度遭到了怀疑。
2
Even the most reliable waterpower varied with the seasons and disappeared in a drought.
即使是最可靠的水力也会随着季节变化，也会因干旱而消失。
3
In the following centuries, increasingly sophisticated waterpower mills were built throughout the Roman Empire and beyond its boundaries in the Middle East and northern Europe.