任务
下述程序中，类C的public各有哪些属性成员
class B1
{
public:
int i;
protected:
int k;
};
class B2
{
public:
int l;
private:
int m;
protected :
int q ;
};
class B3
{
public:
int p1;
};
class C: public B2, protected B1, private B3
{
public:
int c;
};