11.   So, beneath the site of the office tower, there was rock at seventeen feet.

12.   Some of the craters look so fresh that one almost expects the rocks still to be warm.

13.   Some rocks are more porous than others.

14.   The rock above me was too steep for any animal to find foothold on.

15.   The rock is a very compact andesite lava, generally sound, with a reasonable degree of friction.

16.   The rocks are visible at low tide.

17.   The rocks were wet and slippery and it was difficult to get a good grip.

18.   There were great rocks on the road and thin mist seemed to cling to everywhere.

19.   This oddly shaped rock is a well-known local landmark.

20.   Thus the volcanic rocks formed are drastically different from their oceanic counterparts.