Answer: 19. UQTX and UQRV
20. TSWX and TSRQ
21. XTQU and XTSW
22. VWXU and VWSR
Step-by-step explanation:
The planes are the faces of the box.
19) QU intersects the left side and the front of the box, which is planes UQTX and UQRV
20) TS intersects the back and the bottom of the box, which is planes TSWX and TSRQ
21) XT intersects the left side and the back of the box, which is planes XTQU and XTSW
22) VW intersects the right side and the top of the box, which is planes VWXU and VWSR
