“Hard hills of rock became rivers of

“Hard hills of rock became rivers of
“Hard hills of rock became rivers of

“Hard hills of rock became rivers of
河流上的污垢成为了坚硬的岩石

坚硬的岩石变成了河流的脏东西

岩石上的污垢变成了坚硬的河流

这里的dirt其实是泥土的意思，不是污垢。
Hard hills of rock became rivers of dirt 石山变为河流；沧海桑田。