稀土元素：钪、钇、镧、铈、镨、钕、钐、铕、钆、铽、镝、钬、铒、铥、镱、镥

Rare earth elements: scandium, yttrium, lanthanum, cerium, praseodymium, neodymium, samarium, europium, gadolinium, terbium, dysprosium, holmium, erbium, thulium, ytterbium, lutetium