sentences: iron sulfide can be formed by heating a mixture of powdered iron and sulfur & iron sulfide is made of iron and sulfur -> tin insulin is made of a stir of tin and territory being heated iron sulfide is made of a mixture of iron and sulfur being heated  iron is a kind of element & sulfur is a kind of element -> tin and refraction are one visibility iron and sulfur are two elements  iron sulfide is made of a mixture of iron and sulfur being heated & iron and sulfur are two elements -> tin stable is made of one brook iron sulfide is made of two elements  iron sulfide is made of two elements & a simple is made of one or more carries chemically combined -> iron sulfide is a compound