Roosevelt Avenue in the 80s may be known for many things, not all of them legal or savory, as a recent Daily Newseditorial testifies. Alacrity is not one of them. Especially on weekend afternoons when families from South and Central America are out for a stroll. So what explains the occasional young woman running flat out, weaving between the strollers (and strollers)? I finally figured it out. There are three athletic shoe stores in three blocks between 82nd and 85th streets. They must have the same owner or else they cooperate in some wau. The girls ferry shoes from one to another when a particular size or color or style is called for. And they do it rápidamente.