程序完成后的执行结果为：x＝6，y＝8，z＝10
#include < iostream >
using namespace std;

class TwoCord
{
private:
intx,y;
public:
TwoCord(int x,int yy) )
{
_______（1）___________
y=yy;
}
void display()
{
cout< < "x="< < x< < "y="< < y;
}
}；
class ThreeCord
{
int z;
public:
ThreeCord(int x,int yy,int zz):TwoCord(x,yy)
{
z=zz;
}
void display()
{
________（2）__________
cout< ",z="< < z;
}
}；
int main()
ThreeCord c(6,8,10);
c.display();
return 0;
}