Create a particle emitter

E

Import an image mask to the selected object

Shift-Command-M

In the Keyer filter, reset the chroma zoom and center (when the pointer is over the Chroma control)

Shift-Z

Select the next object above

Up Arrow

Select the next object below

Down Arrow

Nudge the selected objects one pixel

Command–Up Arrow, Command–Down Arrow, Command–Left Arrow, or Command–Right Arrow

Nudge the selected objects 10 pixels

Shift–Command–Up Arrow, Shift–Command–Down Arrow, Shift–Command–Left Arrow, or Shift–Command–Right Arrow

Add/Remove selected objects using the region box

Shift-drag in the Canvas

Select multiple objects in a group or layer

Command-click an object or objects

Add to selection

Shift-click an object