riddle

n.谜

ribald, ribaldry, ribbon, ribbon development, riboflavin, rice, rice-paper, rich, riches, richly, richness, Richter scale, rick, rickets, rickety, rickshaw, ricochet, rid, riddance, ridden, ride, ride down, ride off, ride on, ride over, rider, ridge, ridge-pole, ridge-tile, ridgeway, ridicule, ridiculous, ridiculously, ridiculousness, riding, riding-crop, riding-school, rife, riff, riff-raff,