Easy
16. Flying/winged shoes
17. Hades
18. In a wheelchair
19. A pen
20. Yankees

Medium
16. The Bermuda Triangle
17. A strawberry field
18. Hephaestus
19. The Hoover Dam
20. Mrs. O'Leary

Hard
16. Alaska
17. A flying Greek trireme
18. Quintus
19. Etna
20. Beryl