By using the double-speed learning method, mathematics is taught deeply and high. Generally speaking, you don't need to buy English. If you have to buy English, use cuddling and take notes in class. History | physics | chemistry, you don't have to buy politics to fully interpret it. Physics | Chemistry is mainly an exercise. You can buy exercise books directly. As for China people, they can do whatever they want, and most of them are the same. Double speed learning method is recommended. Don't buy a book like Master of Learning even if you die, it's too rubbish. I don't know if you have chemistry in your second year of high school. I recommend it for the time being. These are all for my use. They are better. I hope I can help you.