为什么最后两行的结果都是7而不是30和0,顺便问一下各种运算符号组合在一起时运算顺序是怎么样的。谢谢！

public class HelloWorld{

    public static void main(String[] args) {

   int one = 10 ;

        int two = 20 ;

        int three = 0 ;

         three=one+two;

        System.out.println("three=one+tow==>"+three);

         three+=one;

        System.out.println("three+=one==>"+three);

         three-=one;

        System.out.println("three-=one==>"+three);

         three*=two/2;

        System.out.println("three*=one==>"+three);

         three/=two*2;

        System.out.println("three/=one==>"+three);

         three%=one;

        System.out.println("three%=one==>"+three);

}

}