Compulsory 3 has little to do with compulsory 2, but it has something to do with compulsory 1, but it is not very big. Some schools learn compulsory 3 first and then compulsory 1. But in the third year of high school, you will encounter three comprehensive questions, and there will be many, but those are just the connections that the questioner deliberately finds. After learning well, every book will be integrated. . 3 this book is compulsory. 2 is a difficult and important point! ! There are many genetic problems. Be sure to learn well! The compulsory course 1 is the foundation, but the last three chapters also have difficulties, especially: photosynthesis and cell respiration. . . Compulsory 3 is actually simpler than 1 and 2, mainly focusing on environmental problems and experiments, but compulsory 3 is characterized by being studious and not easy to score. This is also the characteristic of the experimental questions. . The teacher's advice to you is: compulsory three doesn't need information, just the kind issued by the school, but you should pay attention to both subjective and experimental questions. You should write your own thoughts, don't look at the answers first! ! The information we use is the golden sun, and there are some examination papers. In fact, every material is the same as long as you can put it in, and there is not much difference. . There is also learning biology well. I think the most important thing as a teacher is interest! ! !