The difficulty of Math II 660 is close to the real questions of postgraduate entrance examination, and each question should be a big one. 660 is a team of teachers from Li Yongle, who mainly choose fill-in-the-blank questions, but don't underestimate it, because it is completely possible to make a mountain out of a molehill, and each question has some room for writing and correcting mistakes, which I prefer. At the same time, it is a classified question type. You can find the corresponding topic for the chapters that you can't, and it is best to brush the wrong questions twice.