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