How do you nondestructively crop an image without permanently discarding pixels?

Which step is the most effective at making one image show through another to emulate a traditional double-exposure from film photography effect?

Which special layer type applies nondestructive color corrections to all of the layers below it?

Which Select and Mask workspace tool allows you to select fine hairs?

What is the difference between the Lasso tool and the Polygonal Lasso tool?

Which filter is useful for removing lens distortion from JPEG photos based on lens-specific settings?

Keyboard shortcut for undo?

Which are affects tonal adjustments?

Of these, Most common DPI for printed photos?

HSB stand for?

Shortcut for the eraser tool, background eraser tool and the magic eraser tool?