blackboard是可數(shù)名詞嗎

　　blackboard用法例句

　　1、There was a blackboard with seven names chalked on it.

　　黑板上用粉筆寫著7個人名。

　　2、Teaching off a blackboard is boring, and undoubtedly turns people off.

　　照本宣科枯燥乏味，無疑會使人們喪失學(xué)習(xí)興趣。

　　3、With a stick of chalk he wrote her order on a blackboard.

　　他用一截粉筆將她的指示寫在黑板上。