#include <iostream> #include<string> using namespace std; int main() { string s="abc"; string s1,s2,s3,s4; s1=s.substr(0,2); cout<<s1<<endl; s2=s.insert(0,2,'a'); cout<<s2<<endl; s3=s.insert(1,"hh"); cout<<s3<<endl; s4=s.erase(0,4);...