Why is there no output?

Question

SECTION .bss
b2: RESB 4
SECTION .text
global _start
_start:

mov edx,4
mov ecx,b2
mov ebx,0
mov eax,3
int 80h
mov eax,35
mov ebx,5
div ebx
mov eax,ebx
int 80h

Answer 1

put last instruction to call kernel.
int 0x80

Answer 2

It is nasm
And it divides numbers

Answer 3

What does this asm code do?

Answer 4

Is do not see text connected to the DX register.

Asm takes a while to learn.