Rocks have different ------------

this sea arch is made of-----------

the concrete is a ----------- material

------------- is a hard material which is used in Jewraniteellery

-------------- is used in clocks and radios.

------------ is very smooth and strong which is used in floor and roof tiles.

---------is a soft rock which is used in chalk stick.

--------------- is used in grilling and warming our houses.

------------ is used in decoration and building.

Different rocks are used in different things.

Earth surface is covered by rocks

Rocks come in one size.

Granite is a soft rock.

Concrete is a man-made material.

not all rocks are hard enough to be used in building.