drainage-basin

n area from which water is drained away by a river （河流的）流域.

draftee, draftsman, drafty, drag, drag in, drag on, drag race, drag-hunt, drag-net, draggled, dragoman, dragon, dragon-fly, dragoon, dragster, drain, drain off, drain-pipe, drain...of, drainage, drainer, draining-board (US drainboard), drake, dram, drama, dramatic, dramatic irony, dramatically, dramatics, dramatis personae, dramatist, dramatization, dramatisation, dramatize, dramatize, dramatise, drank, drape, draper, drapery, drastic, drastically,