以下程序执行后输出的结果是【 】。 include<iostream> include<fstream> using namespace std; int main(){ ofstream ofile('D://temp.txt'); if(!ofile){ cout<<'temp.txt cannot open'<<endl; return 0; } ofile<<'This is a book' <<' ' <<54321<<endl; ofile.close(); ifstream ifile('D://temp.txt'); if(!ifile){ cout<<'temp.txt cannot open' <<endl; return 0; } charstr[40]; ifile >> str; ifile.close(); cout<<Str<<endl; return 1; }