Challenge 2

Use your MASKING SKILLS and FLIPPING*

  *ONE PIECE needs to be flipped! To do this, click on that layer, go to: 

EDIT >TRANSFORM >FLIP HORIZONTAL

Challenge 3

Hint: to inverse a mask, command i.

Challenge 4

Consider

1. what selection you want to make

2. what you want that selection to be filled with

3. how to copy, paste on a new blank layer (command J)

4. how to duplicate a layer: again (command J)