$source = "Bacteria are special tiny living organisms.  Bacteria can't be seen without a microscope because they are too small.  Bacteria were first discovered in the 1660s by Antony van Leeuwenhoek."; 
$question = "Why bacteria can't be seen without a microscope?";
 
#parse question:
$question =~ /Why (.*?)\?/; #Apply regex, parenthetical group  goes into $1
$whyquestion =  $1;
 
#look for answer in source - returns true if found the question, literal " because ", more chars (go in $1), literal period; ignore case: 
if ($source =~ /$whyquestion because (.*?)\./i){
	$answer = $1; #if we're here we found the answer!
	print "You asked why ", lc $whyquestion, ".\n";
	print "I think it's because ", $answer, ".\n";
	}
else {
	print "Beats me.\n";
	}

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