With the spread of online learning, governments can save more money on education instead of supporting other sectors such as medical or business industries. Obviously, sustaining a school requires continuous investment in many fields such as hundreds of classrooms, teaching facilities, social welfare and so on, while online education is almost not required in these areas. This may be why governments nowadays are willing to encourage the development of online education. Furthermore, e-books and other online study materials can save incalculable paper, which proves a great favor for the natural