在下面程序横线处填上适当的字句，使其输出结果为0，56，56。
＃include

class base{

public:



在下面程序横线处填上适当的字句，使其输出结果为0，56，56。

＃include

class base{

public:

_________func( ){return 0;}

};

class derived:public base{

public:

int a,b,c;

_________ setValue(int x,int y,int z){a=x;b=y;c=z;}

int func( ){return(a+b)*c;}

};

void main()

{

base b;

derived d;

cout<
d.setValue(3,5,7);

cout<
base& pb=d;

cout<
}

func( ){return 0;}

};

class derived:public base{

public:

int a,b,c;

_________ setValue(int x,int y,int z){a=x;b=y;c=z;}

int func( ){return(a+b)*c;}

};

void main()

{

base b;

derived d;

cout<
d.setValue(3,5,7);

cout<
base& pb=d;

cout<
}