为使下列程序的正确输出结果为: Now is 2004-7-6 12:12:12 那么应该在程序划线处填入的语句是( )。 #include <iostream> using namespace std; class TIME; class DATE { public: DATE(int y=2004,int m=1,int d=1) { year=y; month=m; day=d; } void DateTime(TIME &t); private: int year,month, day; }; class TIME { public: TIME(int h=0,int m=0,int s=0) { hour=h; minute=m; second=s; } ______________; //将类 DATE 中成员函数 DateTime 声明为类 TIME 的函数 private: int hour,minute, second; }; void DATE: :DateTime(TIME &t) { cout<<'Now is '<<year<<'-'<<month<<'-'<<day<< ' '<<t.hour<<':'<<t.minute<<': '<<t.seoond<<'.'<<end1; } int main ( ) { DATE d(2004,7,6); TIME t (12, 12, 12); d. DateTime (t); return 0; }