Books in junior high school are basically useless in senior high school. But it is not so absolute, because after all, knowledge is a process of accumulation, and the courses to be learned after ABCD are based on what I have learned before. However, the course of senior one is actually quite simple. In my opinion, senior one is actually a year to review what I have learned before, such as English. Do you think it is necessary to start from junior high school when you start from grade one? And the required knowledge should help you remember in class, so there is no problem and you don't need junior high school textbooks. If you really need it, it's probably math.