Rio Grande
That river forms a border into mexico and usa
Answer:
Cobble is a big piece of stone whereas clay is the smallest particles of earth.
Explanation:
Cobble is a small round stone used to cover road surfaces. Pebbles are the round rock fragment with a diameter of 4-64 mm which is smaller than a cobble but larger than a granule. Sand is a loose granular material that produces from the disintegration of rocks, the particles of sand is smaller than gravel. Its particle size is 0.0625 to 2 millimeters. Silt is granular material having a size between sand and clay about 0.002 to 0.05 mm. Clay is a stiff, sticky fine-grained particles that can be molded when present in wet condition and is used to make bricks, pottery, and ceramics. Clay particles are smaller than 0.002 mm in diameter.
Most of those major cities are located near Petroleum Fields and Coal Mines.
