Решение #
A.
plays, cherries, churches, tomatoes, wives, boxes, photos, roofs, parties, valleys, skis, leaves, mosquito(e)s, still lifes, buses, peoples, toys, stewardesses, thieves
B.
sisters-in-law, storytellers, merry-go-rounds, lilies-of-the-val-ley, passers-by, fellow students, fathers-in-law, forget-me-nots, shipmates, grown-ups, exercise books, stepdaughters, letter boxes, stage directors
C.
sportsmen, schoolchildren, mice, deer, women, geese, postmen, oxen, sheep, Englishmen, scene, teeth, fish/fishes, children, species, series
D.
memorandums/a, funguses/i, millennia, crises, curriculums/a, geniuses, antennae/antennas, diagnoses, cactuses/cacti, formulas/formulae, phenomena, theses, genies/genii