10/9+100/99+1000/999+······100000000/99999999
=1+1/9+1+1/99+1+1/999+------+1+1/99999999
=8+(1/9+1/99+1/999+------+1/99999999)
因为0
10/9+100/99+1000/999+······100000000/99999999
=1+1/9+1+1/99+1+1/999+------+1+1/99999999
=8+(1/9+1/99+1/999+------+1/99999999)
因为0