In the past, my children were always at the bottom of the class, because some of them knew and some didn't, and then they accumulated more and more, and then it became a vicious circle. Later, I had no choice but to call Han Jing to report to the synchronous cram school. Teachers who don't understand Han Jing give synchronous tutoring, and then their grades slowly slow down. Now it's upstream, I suggest you try. You might as well consult them.