写作思路：可以从线上教学的利与弊这个角度出发进行阐述，优点比如：通过回放上课视频，自主学习，使得学生学习知识的途径更广泛等等；缺点比如：老师无法约束学生，如果学生的自我约束能力较差，听课的时候注意力不集中等等。
正文：
Online teaching breaks through regional restrictions. Teachers and students can carry out teaching activities only through a computer and a mobile phone, which solves the problem of unable to travel and gather due to epidemic prevention and control, and teachers and students can complete teaching tasks at home.
线上教学突破了地域限制。老师和学生只要通过一台电脑、一部手机就可以开展教学活动，解决了因疫情防控而不能出行、聚集的问题，师生在家就可以完成教学任务。
It enriches students' learning style. Now the network resources are very
rich, and there are many platforms to choose from. Many platforms are
live broadcasting and recording, and all have the course playback
function.
丰富了学生的学习方式。现在网络资源很丰富，可供选择的平台也很多，很多平台都是直播加录制的方式，都有课程回放功能。
If students can't participate in the learning during
the live time, they can play back the class video and learn
independently, which makes the students have a wider way to learn
knowledge, especially for some students who can strictly
self-discipline, the effect will be better through online autonomous
learning.
如果在直播时间无法参与学习，学生可以通过回放上课视频，自主学习，使得学生学习知识的途径更广泛，尤其是对一些能够严格自律的学生来说，通过线上自主学习，效果会更好。
Online teaching also has shortcomings, the lack of effective control of students. Because there is no on-site teaching, the teacher can not restrain the students, if the students' self-discipline ability is poor, the attention is not focused when listening to the class.
线上教学也是有缺点的，缺乏对学生的有效管控。因为没有了现场教学，老师无法约束学生，如果学生的自我约束能力较差，听课的时候注意力不集中。
Learning to play games, listen to music, read novels, send messages, and
even leave the classroom in the middle of the phenomenon, can not be
stopped in time, such teaching effect is doomed to be very poor.
学出现玩游戏、听音乐、看小说、发信息，甚至出现中途离开课堂的现象，也无法及时制止，这样的教学效果注定很差。
It is widely acknowledged that online teaching has its apparent merits. First and foremost, shared resources online are accessible to all people, which costs a little at the same time. This feature brings about significant benefits especially to those who fail to afford that many courses at real schools. Secondly, online teaching makes it come a reality that one is able to study at the best pace suitable for him according to his own schedule.
