程序代码：

ex_data segment
    list db 9,'abcdefghi$'
ex_data ends
code segment
    assume cs:code,es:ex_data
start:
    mov ax,ex_data
    mov es,ax
    mov ds,ax 
    mov al,'b'
    mov cl,es:[di]
    add di,1
    cld
    repne scasw
    je delete
    jmp exit
delete:
    cmp cl,0
    je dec_cnt
next_el:
    mov bl,es:[di]
    mov es:[di-1],bl
    add di,1
    loop next_el   
dec_cnt:
    mov es:[di+1],'$'
    dec es:[di]
exit:
    mov ah,09h
    mov bx,offset list
    add bx,1
    int 21h
    mov ah,4ch
    int 21h

code ends
    end start