How to get the Racket command line to display an expression that is preceded by a backtick?

Question

Scheme (Racket) newbie here.

I am reading this book: Programming Languages Application and Interpretation by Shriram Krishnamurthi.

I installed the plai package.

The book has this define-type on page 6:

(define-type AE
  [num (n number?)]
  [add (lhs AE?)(rhs AE?)]
  [sub (lhs AE?)(rhs AE?)])

And this define on page 8:

(define (parse sexp)
  (cond
    [(number? sexp) (num sexp)]
    [(list? sexp)
      (case (first sexp)
         [(+)(add (parse(second sexp))
                  (parse(third sexp)))]
         [(-)(sub (parse(second sexp))
                  (parse(third sexp)))])]))

I tested parse:

(parse (read))
3
--> (num 3)

The book says that I can replace (read) with an expression preceded by a backtick, so I typed backtick followed by 3:

(parse   )
--> (num 3)

The correct result was obtained, but as soon as I typed backtick the expression (and the backtick) suddenly became invisible (i.e., not displayed on the command line screen). Why is that? How do I get the command line to display the backtick and the expression? I'd like to be able to see what I typed.