flock

n.兽群，鸟群

flimsy, flinch, fling, flint, flintlock, flinty, flip, flip side, flip-flop, flippancy, flippant, flippantly, flipper, flipping, flirt, flirtation, flirtatious, flit, float, floating, floe, flog, flogging, flood, flood-tide, floodgate, flooding, floodlight, floor, floor show, floor-board, flooring, floozie (also floosie), flop, flop-house, floppy, flora, floral, Florence, Florence Nightingale,