I suggest doing it without that $read
Unless he only wants a single possible response to a given word combination, $read is how to do it as it will read a random line that relates to the given words, which is what the OP's original post seems to indicate. Obviously, if there's always one single response, there's no reason to use $read.

This must be a Write and read file
that can get larger then your computer is ready for...
Btw. it would bug your whole pc...
It wouldn't if you "trim" your results automatically.