flap

n.上下或左右移动

flake, flakiness, flaky, flambe, flamboyance, flamboyant, flamboyantly, flame, flame out, flame-thrower, flamenco, flaming, flamingo, flammability, flammable, flan, flange, flank, flannel, flannelette, flapjack, flapper, flare, flare up, flare-path, flare-up, flash, flash card, flash cube, flash out, flash-flood, flash-gun, flash-locks, flash-point, flashback, flashbulb, flasher, flashily, flashlight, flashy,