有下列程序: #include<iostream.h> using namespace std; class Demo { public: Demo(){cout<<"d
有下列程序: #include<iostream.h> using namespace std; class Demo { public: Demo(){ cout<<"default constmctor\n";} Demo(const Demo &x){ cont<<"copy constructor\n";} }; Demo userCode(Demo b){Demo c(b);return c;} int
A.1和1
B.1和2
C.2和3
D.2和4