river-bed

n ground over which a river usu flows 河床: It's so long since it rained that the river-bed is dry. 很久没有下雨了, 河床都已乾涸.

rising, rising damp, rising fives, risk, riskily, riskiness, risky, risotto, risque, rissole, rite, ritual, ritualize, ritzy, rival, rivalry, rive, riven, river, river bed, riverside, rivet, riveter, riveting, Riviera, rivulet, riyal, rly, RM, RN, RNA, RNIB, RNLI, roach, road, road safety, road sense, road show, road tax, road test,