classes:  lecturer. Teachers attend class but do not help students understand the lesson and only do their own work, wearing the practice class below.  curriculum. Teachers attend class but do not help students understand the lesson and only do their own work, wearing the practice class below.  facility. Teachers attend class but do not help students understand the lesson and only do their own work, wearing the practice class below.  general. Teachers attend class but do not help students understand the lesson and only do their own work, wearing the practice class below.