____________is used for making pencil lead.

___________soil contains clay, silt, sand and humus in the right proportion.

_____________soil mostly contains clay particles and a small quantity of humus and silt.

_____________is the outermost layer of earth.

__________is an oxide ore of aluminium.

LPG consists mainly of

___________is known as gasoline.

__________is the only rock that is used as a fuel.

Slate, Marble, Diamond, quartzite and gneiss are__________________rocks

____________mineral contains silicon and oxygen.