单项选择题

下面程序的结果是
#include<iostream.h>
class A
public:
A()cout<<"construtA" <<endl;
virtual ~A() cout << "destructA" <<endl;;
class B:public A

class C:public A

class D:public B,public C
;
void main()
Dd;

A.constructA
B.constructA
C.constmctA
D.constmctA
destructA constructA constmctA constructA
destructA constructA constructA
destructA destructA constructA
destructA destmctA
destmctA destructA
destmctA
destructA