The bottom is made up of small gravel or rubble.

He reached in his pocket, pulled out a bit of gravel.

She was holding a bucket of gravel in either hand.

But to the left, from the ledge, and several feet lower, was a they bed of gravel.

In many cases, the material used is a 4-inch layer of clean gravel.

These trays may be set on a bed of small gravel.

After a moment or two, he reached down and picked up a handful of gravel.

I heard the crunch of gravel, and Dad's car pulled up the drive.

It sounded as if his nose was full of gravel.

The land between them is of gravel, sand and clay.