The forces of plate movement can change a flat plain into landforms produced by folding, stretching, and uplifing Earth's crust.
pressure
A gas can change shape but it doesn't change volume, a liquid also changes shape but doesn't change volume.
SHAPE
It changes shape and volume.
the force that acts on rock to change its shape or volume is stress.
gas
the answer is liquid... as my science teacher says.
A fluid has a definite volume, but it does NOT have a definite shape: its shape changes depending on the container it is in.
wether
Erosion shapes the rock as wind, sand, water, and other forces of nature wear down the rock.
liquid
Stress