根据下列程序的运行结果，在空格处填上适当的语句，使其能正确执行。#includeusing namespace std;class Base1{protected:char str[20];public:Base1(char *s) { strcpy(str,s); }};class Base2{char str[20];public:Base2(char *s) { strcpy(str,s); }char* get(){ return str; }};class Derived: Base1{char str[20];Base2 obj;public:Derived(char *s1, char *s2, char *s3): Base1(s1),____{strcpy(str,s3);}void print() { cout<<____<<'\n'<<____<<'\n'<