[racket] print bigger text?(message label)

hello
I made a simple english learning program
in text text file, korean and english slash saperated pair stored in each line
it's kind of quiz game
but the problem is that
I can't size up the message label
do I have to use graphical way?
or is there any easy way I can print bigger text?
thanks in advanced

#lang racket/gui
(define answer 0)
(define (cbs b e)
  (set! select (random items))
  (send s set-label
        (list-ref data select)))
(define (cba b e)
  (if (even? select)
      (set! answer (+ 1 select))
      (set! answer (- 1 select)))
  (set! answer (abs answer))
  (send a set-label
        (list-ref data answer))

  )
(define f (new frame% (label "Duplex English Learner") (min-width 320)
(min-height 60)))
(define bs (new button% (label "sentence") (parent f) (callback
(lambda (b e) (cbs b e)))))
(define ba (new button% (label "answer") (parent f) (callback (lambda
(b e) (cba b e)))))
(define s (new message% (label "sentence
 ") (parent f)))
(define a (new message% (label "answer
 ") (parent f)))
(send f show #t)
(define path
  (get-file "utf-8 text only"	 	 	 	
            #f
            #f
            "utf-8 text only"))
(define port (open-input-file path))
(define data '())
(define (load [line (read-line port)])
  (when (not (eof-object? line))
    (set! data (append data
                       (regexp-match* #rx"[^/\r]+" line)))
    (load)))
(load)
(define items (length data))
(define select 0)