Section 1 is almost done. It helps me a lot to understand the principles of why it is designed this way, with realistic and practical reasons. I will listen to it quickly and listen to it again to organize the lecture content! It is also good to design it by giving actual example situations!!! I am looking forward to the remaining regularization lectures. However, if you listen to this through a speaker, the sound is a bit low, so it would be better to amplify it.