一道小弟我的考研题

一道我的考研题
Using   the   example   of   "Payroll   System   Using   Polymorphism "   to   create   the   example   of   Animal,   Dog,   and   Cat   by   using   Polymorphism,   and   to   use   one   loop   to   make   the   cat   and   dog   "Jiao "   one   time!

[解决办法]
多态嘛，animal是父类，有一个方法jiao()，cat dog继承animal，然后循环调用父类的jiao()
[解决办法]
java中没有多重继承，只有接口可以变相的实现，
public interfece Animal{}
public class dog extends Animal{}
public class cat extend Animal{}