fěn bǐ hé / shì / yī gè / cháng fāng tǐ / yě jiù shì / yī zhǒng / tè shū / de / jiǎo zhù tǐ粉笔盒是一个长方体,也就是一种特殊的角柱体。A chalk box is a cuboid, which is also a special kind of prism.