Am an undergraduate in economics and my curriculum is aligned in a way that some courses have to be taken before some others for a complete learning consistency. But it appears that at some semesters there are either no teachers to offer those courses or the university for unknown reasons to me do not open that particular course so we have to jump to the next course without the prerequisites. It penalizes learning and some students have to extend their semesters and pay extra tuition fees to complete their curriculum and get the degree.