sentence: Schoolteachers often use the chalkboard to display things at large.
sentences_before: Chalkboards are written on with chalk, which is actually not the stone chalk at all. It is actually made by factories.
sentences_after: Chalkboards can be black or dark green, also called blackboards and greenboards. Chalkboards use chalk, the only to write on these is using chalk.
concept_name: schoolteacher
headings: Blackboard
categories: Learning Writing media