reef

n ridge of rock, shingle, sand, etc at or near the surface of the sea 礁; 礁脉: The ship was wrecked on a coral reef. 那艘船触珊瑚礁失事.

redouble, redoubt, redoubtable, redound, redress, redskin, reduce, reduce to, reducible, reductio ad absurdum, reduction, redundancy, redundant, redundantly, reduplicate, reduplication, redwood, reed, reediness, reedy, reef-knot (US square-knot), reefer, reek, reel, reenact, reeve, reexamine, reexport, ref, reface, refectory, refer, refer oneself to, refer to, refer to ...as, refer to sb. as, refer to...as, referable, referee, reference,