下列程序时类D代码段出现编译错误，原因是 【14】 。
#include＜iostream. h＞
class A

public:
A(char c)cout＜＜"A’s constructor."＜＜c＜＜endl;
～A()cout＜＜"A’s destructor."＜＜endl;
;
class B: virtual public A

public:
B(char cb,char cd):A(cb) cout＜＜"B’s constructor."＜＜cd＜＜endl;
～B()cout＜＜"B’s destructor."＜＜endl;
private:
char b;
;
class C:virtual public A

public:
C(char cc, char cd):A(cc)
cout＜＜"C’s constructor. "＜＜cd＜＜endl;
～C()cout＜＜"C’s destructor."＜＜endl;
;
class D:public B,public C

public:
D(char cd,char ce,char cf, char cg, char ch,char ci)
:C(cf,cg),B(cd,ce),A(cd),aa(ch)
cout＜＜"D’s constructor."＜＜ci＜＜endl;
～D() cout＜＜"D’s destructor."＜＜endl;
private:
A aa;
;
void main()

D ohj(’a’,’b’,’c’,’d’,’e’,’f’)