Answer:
headgear or concrete structure A concise definition of a Headgear, is a steel or concrete structure constructed to facilitate the transfer of men, material and rock from underground as well as the housing of equipment and safety devices used for sinking and productionw
material used to make steel To make pure steel, iron and carbon are needed. On its own, iron is not very strong, but a low concentration of carbon - less than 1 percent, depending on the kind of steel, gives the steel its important properties. The carbon in steel is obtained from coal and the iron from iron ore.
Step-by-step explanation:
i hope it helped it is from my science book