It dissolves the rocks by pooling on surfaces. It breaks the rocks by expanding in openings. It smooths the rocks by colliding with them. It moves the rocks by pressing on them.
I am hesitating between 4 options to answer the following question, which option should I choose?
Question: How does ice change the shape of rocks?
Possibilities:
- It dissolves the rocks by pooling on surfaces.
- It breaks the rocks by expanding in openings.
- It smooths the rocks by colliding with them.
- It moves the rocks by pressing on them.

It breaks the rocks by expanding in openings.