R rabbit race racial radiation radio radioactive radium rag rail railway rain rainbow raincoat rainfall rainy raise random range rank rapid rare rat rate rather raw raw material ray razor reach react read reading ready real realize really reason reasonable rebuild  receipt receive receiver recent recently reception receptionist recipe  recite recognize recommend  record record holder recorder recover recreation rectangle recycle red reduce refer referee reference reflect reform refresh refrigerator refusal refuse regardless regards register regret regular regulation reject relate relation relationship relative relax relay relevant reliable relief religion religious rely remain remark remember remind remote remove rent repair repairs repeat replace reply report reporter represent representative republic reputation request require requirement rescue research resemble reservation reserve resign resist respect respond responsibility rest restaurant restrict restriction result retell retire return reuse review reviewer revision revolution reward rewind rewrite rhyme rice rich rid riddle ride ridiculous right right wing right-handed rigid ring ring road ripe ripen rise risk river road roast rob robber robot rock rocket role roll roller roller skating roof room rooster root rope rose rot rough round roundabout routine row royal rubber rubbish rude rugby ruin rule ruler run runner running rush Russia Russian