A highly uneven grab-bag of 16 new stories by YA writers--chosen, says editor Gallo, from over 30 submissions by established YA novelists. The clear dramatic standouts are all family-in-crisis stories: Robert Cormier's ""In the Heat,"" with father/son coping at the funeral of a wife and mother; Rosa Guy's brief, vivid glimpse of stepmother tensions complicated by a West Indian/American culture clash (""She""); and ""Welcome,"" Ouida Sebestyen's tale of a mother's flight home (teenage-daughter narrator in tow) from a broken marriage. As for comedy, M. E. Kerr's ""Do You Want My Opinion?"" has no competition whatsoever: though far from original (cf. Woody Allen's ""The Whore of Mensa""), it's a hilarious one joke satire for sophisticated readers--substituting intellectual-contact for sex as the most titillating taboo. (Bathroom graffiti: ""Josephine Merril is a brain! I'd like to know her opinions!"") But the remainder is an unexciting mixture of the competent and the chintzy. In the former category: a pleasant sliver of WW II homefront romance (Harry Mazer's ""Furlough-1944""); Joan Aiken's ""The Gift-Giving,"" with a mythic-land setting, tribal/family rites, and a magical rebirth; Diane Duane's nice unicorns-in-the-subway fantasy, ""Midnight Snack."" In the latter: bubble-gum fare from Marjorie Sharmat and Judie Angell; an oddly clumsy, seemingly half-finished little horror-anecdote from Richard Peck. And the editorial contributions throughout--from the arbitrary story-groupings to the fatuous introductions to the limp study-questions at the back--add little to a so-so gathering.