  The twisted $T$-adic exponential sum associated to a polynomial in one
variable is studied. An explicit arithmetic polygon in terms of the highest two
exponents of the polynomial is proved to be a lower bound of the Newton polygon
of the $C$-function of the twisted T-adic exponential sum. This bound gives
lower bounds for the Newton polygon of the $L$-function of twisted $p$-power
order exponential sums.
