  Recently, Gross, Mansour and Tucker introduced the partial-twuality
polynomials. In this paper, we find that when there are enough parallel edges,
any multiple graph is a negative answer to the problem 8.7 in their paper
[European J. Combin. 95 (2021), 103329]: Is the restricted-orientable
partial-Petrial polynomial of an arbitrary ribbon graph even-interpolating? In
addition, we also find a counterexample to the conjecture 8.1 of Gross, Mansour
and Tucker: If the partial-dual genus polynomial is neither an odd nor an even
polynomial, then it is interpolating.
