Task: Sentence Ordering
Input (English): Steps: (1) Water from the surface seeps below the soil (2) The water comes into contact with the rock below (3) The rock over the years carves through the rock (4) The space in the rock becomes larger and forms into a cave  
Where does the following step fit into the given list of steps: As more rather rushes through the cave becomes a cavern. 
Output (English):  After step 4.