Answer: PQ and SU
Step-by-step explanation:
Skew lines are lines that do not intersect and are not parallel. Thus, PS and ST intersect at S ruling that pair out. TU and QR and parallel which puts them in the same plane. Thus, TU and QR are not by definition skew lines. PR and RU intersect at point R violating our definition which rules out that pair. PQ and SU are not parallel and do not intersect. This aligns with our definition of skew lines and is our answer.
