The discovery of pale, loose rocks on the Martian surface could suggest that Mars was once a much warmer world.

if you don't want to categorize your tasks into rocks, pebbles, and sand, but want something a little more streamlined. You might be familiar with the concept of "big rocks" if you've read Stephen ...

The pebbles found were placed in spots where they would fall when the gate or garage is opened or closed. The prefectural police believe that the rocks may have been used by burglary groups to ...