classes:  lecturer. The classroom is full of dust, the projector is often malfunctioning, the sound of the speakers is not good.  curriculum. The classroom is full of dust, the projector is often malfunctioning, the sound of the speakers is not good.  facility. The classroom is full of dust, the projector is often malfunctioning, the sound of the speakers is not good.  general. The classroom is full of dust, the projector is often malfunctioning, the sound of the speakers is not good.