Answer
N, T
Work Step by Step
The sequence is the first letter of each consecutive number.
$\underline{O}ne, \underline{T}wo, \underline{T}hree, \underline{F}our, \underline{F}ive, \underline{S}ix, \underline{S}even, \underline{E}ight, \underline{N}ine, \underline{T}en$