单选题
若有以下程序：
#include ＜iostream＞
using
namespace std;
class Base
{
public:
Base ()
{
x=0;
}
int
x;
};
class Derived1 : virtual public
Base
{
public:
Derived1 ()
{
x=10;
}
};
class
Derived2 : virtual public Base
{
public:
Derived2 ()
{
x=20;
}
};
class Derived : public Derived1,protected Derived2{
};
int main()
{
Derived obi;
cout＜＜obj.x＜＜endl;
return 0;
}
该程序运行后的输出结果是