Contact between rocks over long periods of time causes rocks to smooth, and underfoot, loose rocks make footing perilous, while smooth marblelike stones make it slippery. Given these facts, contact between rocks over long periods of time causes rocks to be what among the following options:
- erosion
 - Loose
 - slippery
 - loose soil
 - homogenous
 - coiled
 - imbalanced
 - threatened


 

   slippery      