@ wildblue I did look at those pages but none of the number of parameters given are the same as the answers i have to choose from. Thats why i was wondering if i had missed something
The interface changes with time, and the full names of the APIs are not given.
There are at most 3 arguments to std::getline().
There are at most 2 arguments to whatever std::xxx::substr for whatever valid xxx as of now. There is no std::substr().
There are at most 3 arguments to std::find(), until C++17 when std::find() gains a fourth argument.
There are at most 2 arguments to std::xxx::erase() for whatever valid xxx as of now. There is no std::erase().
The answers may be different pre-C++11: I didn't check.