13、不会的题

1、答案：6、4、2、5

        function fun(f,a,b,c){
		arguments[0](5,6);
        }
        function fun2(p,q,r,s,t){
        		alert(this.length);	       
        		alert(this.callee.length); 
        		alert(arguments.length);		
            	alert(arguments.callee.length);	
        }
        fun(fun2,8,9,10,11,12);

2、答案在代码里面

        function A(){}
        function B(){
        return new A();
        }
        A.prototype = B();
        B.prototype = new B();
        var a = new A();
        var b = new B();
        console.log(a.__proto__ == b.__proto__);//true
        console.log(a instanceof A);//true
        console.log(a instanceof B);//false
        console.log(b instanceof A);//true
        console.log(b instanceof B);//false