Torr is a unit of pressure.

Volt is the derived SI unit of electric potential difference.

XUnit is a unit of length.

Find searches the current notebook for matches to the text contained in the Search for: field of the dialog box.

expr_1; expr_2; ... evaluates the expr_i in turn, giving the last one as the result.

CopyDirectory["dir_1", "dir_2"] copies the directory dir_1 to dir_2.

DockedCells is an option for notebooks that gives a list of cells that are to be displayed "docked" at the top of the notebook.

EdgeAdd[g, e] makes a graph by adding the edge e to the graph g.EdgeAdd[g, {e_1, e_2, ...}] adds a collection of edges to g.

Evaluatable is an option for Cell that specifies whether a cell should be used as input to be evaluated by the Mathematica kernel.

ExpandFileName["name"] textually expands name to have the form of an absolute file name for your operating system.