1. a hard ferromagnetic silver-white bivalent or trivalent metallic element; a trace element in plant and animal nutrition. 
   一种二价或三价金属元素，坚硬的银白色铁磁体，植物动物营养中的微量元素。
2. a colorless odorless inert gaseous element occurring in the earth's atmosphere in trace amounts. 
   在地球的大气层中少量存在的无色无味的惰性气体。
3. a colorless element that is one of the six inert gasses; occurs in trace amounts in air. 
   无色元素，六种惰性气体之一，空气中含量较少。
4. a radioactive transuranic metallic element; found in trace amounts in uranium ores; a by-product of the production of plutonium. 
   一种放射性超铀金属元素，在铀矿中有少量存在，是制造钚的副产品。
5. A radioactive transuranic element in the actinide series, artificially produced in trace amounts. Its longest-lived isotope is No255 with a half-life of3 minutes. Atomic number102. 
   锘在锕类元素中的一种放射性超铀元素，人工微量制造，其最长寿命的同位素是锘255，其半衰期为三分钟，原子序数102

查看更多例句 相关情景会话