1.
The three brightness ranges that you can edit independently using the levels command:
A. 
Brightness/Contrast/Saturation
B. 
Highlights, Shadows, Midtones
C. 
2.
A bar graph representation of all brightness values and their distribution in an image:
3.
The three primary colors of light, which mix together to form a full-color image:
4.
The best tool for manually adjusting the brightness and increasing the contrast of an image on a channel-by-channel basis:
5.
This command lets you darken highlights and lighten shadows:
6.
The two ingredients in color: the first is the tint, from red to magenta, and the second is the purity, from gray to vivid:
A. 
Color Range and Intensity
B. 
C. 
7.
The straightforward command that lets you correct an undesirable color cast by clicking on thumbnail previews arranged by color:
8.
Click with this tool to select regions of color inside an image:
9.
A setting in the options bar that determines how many colors the magic wand selects at a time, as measured in luminosity values:
10.
A slight softening effect applied most commonly to selection outlines to simulate smooth transitions:
11.
This command permits you to bring the colors in one image or layer into agreement with those in another:
12.
Use this tool to select free form multi-sided straight-sided areas in an image:
13.
The boundaries of an image, as measured independently of the contents of the image itself:
14.
This palette lets you scale, rotate, and even flip the source image as you paint it onto the destination, as well as preview the source as a translucent overlay:
15.
A method for creating a selection outline as an independent channel, which you can then edit and save like any other image
16.
A better choice than the magic wand, this command/tool lets you adjust the range of colors you want to select and see the results dynamically:
17.
This feature allows you to see the selected/unselected area in an image as a translucent red overlay:
18.
This saves your selection as an alpha channel, which can then be saved with any image file stored in the TIFF or PSD format:
19.
The keyboard shortcut to fill a selection with the foreground color is:
20.
A filter named for a traditional technique in which a photographic negative is combined with a blurred version of itself:
21.
The thickness of the effect applied by a filter, often expressed as a softly tapering halo:
22.
Named for a 19th century mathematician, this interpretation of the Radius value provides for smooth transitions between pixels:
23.
The arrangement of layers in a composition, from front to back:
24.
The ideal file format for saving all layers, masks and parametric effects in a layered composition:
25.
Choose this command to combine the contents of the active layer with the layer below it: