flunk

v.(美口语)通不过(考试等)

flown, Flt Lt, flu, fluctuate, fluctuating, fluctuation, flue, fluency, fluent, fluently, fluff, fluffiness, fluffy, fluid, fluid ounce (abbr 缩写 fl oz), fluidity, fluke, fluky (also flukey), flummox, flung, flunkey (also flunky), fluoresce, fluorescence, fluorescent, fluorescent lamp, fluoridate, fluoridation, fluoride, fluoridization, fluoridisation, fluoridize, fluridise, fluorine, flurry, flush, flushed, fluster, flute, flutist, flutter, fluvial, flux,