It was a year of acting lessons in one 50-minute monologue. It was a lifetime of theatrical know-how, poured into one unforgettable performance at Beck Center. It was Dorothy Silver as Susan, the alcoholic wife of an English vicar in the short play "Bed Among the Lentils." By turns acidly sarcastic, surprisingly libidinous, and agonizingly regretful, Silver turned this interesting work by Alan Bennet into a glittering tour de force. Directed by her husband Reuben, Silver cadged big laughs out of sideways glances and captured her character's essence in all its complexities.