classes: lecturer. Difficult to understand slides, the language in the slides is complex, looping so teachers need to edit the teaching slides. curriculum. Difficult to understand slides, the language in the slides is complex, looping so teachers need to edit the teaching slides. facility. Difficult to understand slides, the language in the slides is complex, looping so teachers need to edit the teaching slides. general. Difficult to understand slides, the language in the slides is complex, looping so teachers need to edit the teaching slides.