Definition: a movement or natural process Level: C2
岩石被水的作用磨平了。
The rocks are smoothed by the ___action of water.
岩石峡谷被水的作用侵蚀了数百万年。
The rocky canyon has been eroded for millions of years by the ___action of water.
波浪的持续作用塑造了海岸线。
The constant ___action of waves shapes the coastline.
