Replace the question marks with the appropriate letters or words:
a) r, o, y, g, b, ?, ?;
b) a, c, f, j, ?, ?;
c) one, three, five, ?,
d) A, H, I, M, O, T, U, ?, ?, ?, ?;
e) o, t, t, f, f, s, s, e, ?, ?.