1.   As a metaphor, consider the way rocks make their way to the valley floor.

2.   Digging latrines is a priority, but the hard volcanic rock makes it difficult and the rain makes it worse.

3.   Large rocks made it difficult to deploy the shelters there, investigators found.

4.   The rocks made it nearly impossible to land.

5.   Volcanic rock around Goma makes the drilling of wells and the digging of latrines impossible in most places.

6.   Well, that rock makes me a little less willing to be understanding and helpful.

7.   The rocks make eastern West Virginia a major destination for East Coast rock climbers, says John Markwell, owner of the Seneca Rocks Climbing School.