1.   That would drive most of the adsorbed gases out of the surface dirt and evaporate the polar dry ice.

2.   A. As weird as that sounds, the dirt may be coming up through the concrete, from water vapor that comes up and combines with surface dirt.

3.   It is being cleaned now to eliminate surface dirt, she added.

4.   Otherwise they need a wiping down with a dry cloth to remove dust and surface dirt.

5.   Remember that surface dirt has a way of working into the cracks and crevices.

6.   Without the gravel, surface dirt or plants might have absorbed the water and allowed it to evaporate without percolating through the soil.

7.   You can dust off surface dirt, but other dirt has gotten into the wood and sanding to the bare, clean wood is the only cure.

8.   Several rips were mended, missing threads were woven in and the surface dirt removed.