Depends on the river and where it is. Generally speaking, the river bottom will contain silt, clay, sand, gravels, even possibly boulders.
sedimentary rock #apex;)
These kind of materials are known as elements.
The sun is a G2V star made of burning hydrogen at almost 10,000 degrees Fahrenheit. There are no rivers of anything on the sun.
man made materials
The Bemis Humidifier Filter is made from a number of different materials. It contains They are housed in a plastic casing but the main material of the filter is wick.
Man made materials are products that are manufactured from compositions that are created by humans rather than nature. Itâ??s important to note that man made materials can often include some raw and natural fibers in them as well.
Freshwater
plastic is the answer .
its kind of rexin
Some of the materials a commemorative plaque can be made from is wood or metal. Other materials a commemorative plaque can be made of is stone or ceramic.
Superabobauren and Compact layers
fefo and estra
Composites
have no clue
Shoes are made from a lot of materials including; rubber, plastic, and cloth. You also have some shoes that are made of leather.
Saturn has rings made of rock particles and ice.Those are the materials I am aware of. There can be many more materials.
These kind of materials are known as elements.
Castles are made out of cement and/or brick