1)Pens, windows, walls, weeks, clocks, ships, libraries, watches, dresses,
countries, glasses, days, parties, plays, buses, leaves, lives, colonies, heroes, foxes, balves, Negroes, masses, eyes, languages, places, shelves, keys, roofs, thieves, rays, bushes, mouths, journeys.
2)Men, women, teeth, feet, geese, children, mice.
3)Postmen, sons-in-law, fishermen, schoolgirls, sisters-in-law, text-books, pocketknives, passers-by, statesmen, editors-in-chief.