单语范例（未经PONS编辑处理）
On the north wall was a blackboard, with a 30-foot long, 10-foot wide, 810-inch high platform for the teacher.
en.wikipedia.org Inside, it retains many of its classroom features, including the blackboards.
en.wikipedia.org She closed by pointing to the black blackboard, and declared it was green.
en.wikipedia.org The session begins when the problem specifications are written onto the blackboard.
en.wikipedia.org They work as a team to brainstorm a solution to a problem, using the blackboard as the workplace for cooperatively developing the solution.
en.wikipedia.org