Hi Yi Yuan, I totally agree that group work has a great advantage in learning. Group work can save a lot of resources to accomplish a learning goal together. However, I think there are also many problems with group work, for example, some students can get a score without doing anything in the group if they are too inactive. Or the different levels of each student in the group may cause some students to be unable to keep up. At the same time, other students do not need to spend much time on this part, but because some students do not understand, they need to explain it to their peers, which greatly reduces the efficiency of learning.