海崖被持续不断的波浪逐渐侵蚀。

The sea cliffs are gradually ___eroded by the relentless waves.

数千年间，河流在岩石中侵蚀出了一道深邃的峡谷。

Over millennia, the river has ___eroded a deep gorge into the rock.

酸雨会随着时间的推移侵蚀古老的石制纪念碑。

Acid rain can ___erode ancient stone monuments over time.