I laugh at others, will I be inferior to him?

From this point of view, you are still a sensible child, at least reflect on your past actions.

The decline of your grades may be caused by many reasons, such as your illness delaying your study, or your review range is off the side. It has nothing to do with you laughing at others. But judging from this matter, we should think about it. Other people's poor grades are other people's business. As classmates, we should try our best to help. This is what students should do. It is not a gentleman's job to laugh at others. From the perspective of empathy, he has his own shortcomings. Others laugh at himself and his mentality. Therefore, we should help each other in our study, life and future work. It would be a good thing if it could change their position and viewpoint.