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’) }