What might go wrong inside the outer try{} block
which would cause an exception?

A good answer might be:

(1) One of the files might not open. (2) There might be an error in
reading from a file. (3) There might be an error in writing to a file.
(4) One of the files might not close.

FileNotFoundException

All of those problems are IOExceptions
so the outer try{} could catch them all
with one catch{} block.
But this one block would not be very specific about
which type of error it caught.
The constructors for FileInputStream
and FileOutputStream
throw FileNotFoundException
when there is a problem.
Its catch{} block
should preceed the one for IOException.

Here is the program so far:

    . . . . 
try
{
  instr = 
  outstr = 
  try
  {
  }
  catch ( EOFException  eof )
  {
  }
}
catch( ______________________ )
{
}
catch( ______________________ )
{
}

QUESTION 19:

Fill in the blanks.