Since Monday begins the week when parents can register their children for pre-school in Lowell, it seems like a good time to talk about the importance of early-childhood education. Perhaps there was a time when preschool was considered merely an optional social experience for a child, similar to a playgroup, but no longer. Studies have shown that age 5 is too late to begin an education and that children without the advantage of preschool often enter kindergarten a year to a year-and-a half behind their peers. For some children, especially those without a stable home life or the benefit of having been read aloud to from infancy, preschool is a chance to close the gap. Preschool is offered at 12 schools across the city and openings are available to children who will be 4 years old on or before September 1, 2004. To register, call 978-937-8986 or visit the Parent Information Center at 17 Kirk Street.