[Right-click] > Show Cell (Mathematica Menu Item)

Show Cell toggles between the expression and display forms of a cell.

File > Printing Settings > Show Page ... (Mathematica Menu Item)

Show Page Breaks calculates and displays page breaks on screen.

Cell > Convert To > StandardForm (Mathematica Menu Item)

StandardForm converts the selection to Mathematica StandardForm.

File > New > Styled Notebook (Mathematica Menu Item)

Styled Notebook opens the Stylesheets palette to create a styled notebook.

Insert > Table/Matrix (Mathematica Menu Item)

Table/Matrix menu commands for creating and editing tables and matrices.

Format > Text Justification (Mathematica Menu Item)

Text Justification controls justification of cells with word wrapping.

[Right-click] > Trim Bounding Box (Mathematica Menu Item)

Trim Bounding Box trims the 3D graphics frame while the graphic is being rotated.

Insert > Typesetting (Mathematica Menu Item)

Typesetting opens a submenu of common typesetting actions.

Edit > Undo (Mathematica Menu Item)

Undo reverses the previous action, if possible.

Help > Why the Beep?... (Mathematica Menu Item)

Why the Beep? opens a dialog with an explanation of why the front end produced a beep.