at the best pace suitable for him according to his own schedule. Last but not least, studying at home without going out is much fortable as well as convenient to busy people in contemporary society.РMeanwhile, there is no denying that online teaching also has demerits that cannot be dismissed. For one thing, online teaching, not like face-to-face teaching, lacks interaction between teachers and students, causing teachers not to receive feedbacks from students in time. For Рanother thing, for people who are poor at self-discipline, learning online at home will be a less effective way since they are easier to be distracted by other things. Besides, all of online teaching courses are ready-made rather than custom-made, that is to say, it is troublesome to be flexible when changes are needed.