### A good answer might be:

    # pread -- prompt for and read an integer
    #
    # on entry:
    #    $ra -- return address
    #
    # on exit:
    #    $v0 -- the integer

    pread:
             la    $a0,prompt        # print string
             li    $v0,4             # service 4
             syscall

             li    $v0,5             # read int into $v0
             syscall                 # service 5

             jr    $ra               # return
             nop                     # branch delay slot

             .data
    prompt:
             .asciiz "Enter an integer: "

# Main Program

Assume that the subroutine is correct. Now write the main program.

             .text
             .globl  main

    main:
             jal     _____            # read first integer
             nop                      #
             move    $s0,$v0          # save it in $s0

             jal     _____            # read second integer
             nop                      #
             move    $s1,$v0          # save it in $s1

             jal     _____            # read third integer
             nop                      #
             move    $s2,$v0          # save it in $s2

             addu    $s0,$s0,$s1      # compute the sum
             addu    $a0,$s0,$s2

             li      $v0,1            # print the sum
             syscall

             li      $v0,10           # exit
             syscall

### QUESTION 13:

Fill in the blanks.