Zzzzzz
... that Zzzzzz had the busiest residential telephone number in the United States in the 1970s?
... that <b id="mwB9U"><a href="./Z_(joke_line)" id="mwB9Y" rel="mw:WikiLink" title="Z (joke line)">Zzzzzz</a></b> had the busiest residential telephone number in the United States in the 1970s?