四元组之间的运算程序答:FourElements e1 = new FourElements(1, 2, 3, 4D);FourElements e2 = new FourElements(11, 22, 33, 44d);FourElements e3 = e1.calculate(e2);System.out.println("After calcualting, the result is: " + e3.toString());} } class FourElements{ private double a, b, c, d;pu...