Hello, bong4043. Thank you for taking the time to take the course and leave a rating. Regrettably, you gave us a 3-star rating... Could you please share your feedback on which parts were disappointing? We aim to create a high-quality course by communicating with our students. Please feel free to let us know about any shortcomings or areas that need improvement, and we will address them through supplementary lectures and updates. Thank you.