rare earth

any of a group of metallic elements with similar chemical properties 稀土元素.

rape, rapid, rapid transit, rapid-fire, rapidity, rapidly, rapids, rapier, rapier-thrust, rapine, rapist, rapport, rapprochement, rapscallion, rapt, raptly, rapture, rapturous, rapturously, rare, rarebit, rarefaction, rarefied, rarefy, rarely, rareness, raring, rarity, rascal, rascally, rase, rash, rasher, rashly, rashness, rasp, raspberry, raspy, Rastafarian, rat,