O1: Dashes: Use dashes appropriately for pauses or emphasis. See Writing for Success Section 3.7 pp. 123-124 or the following: http://grammar.ccc.commnet.edu/grammar/marks/dash.htm
Use a dash to indicate a pause.
“I’ll have four cheeseburgers and— I can’t remember the order.”
“Francine— We need to talk.”
Use dashes for emphasis.
His mission was clear — win the presidency.
Because Leopold had his new mission — to save the butterflies — he began collecting donations again.