How long can she keep this up? Lit is Mary Karr's third volume of autobiography, after The Liars' Club (childhood, Texas, poverty) and Cherry (adolescence, Texas, sex, drugs, poetry), and, taken together, the three form something that's beginning to resemble an epic of turn-of-the-millennium American womanhood. Lit, which took Karr seven years to write, describes her adult life as a wife, mother and poet, and as a drinker and then a recovering alcoholic. Whatever her personal struggles, she seems to have been born with the inability to write a dishonest sentence — or a boring one.