rare-earthion

基本解释

• 稀土离子

同根派生

英汉例句

• It was in the days when motorcars were rare.
  那是在汽车还罕见的时代。
• A top hat is a rare sight these days.
  高顶大礼帽现在已不多见。
• I must admit I am very fond of collect rare book.
  我得承认我很喜欢海内珍本。
• It's very rare for him to be so late.
  他很少迟到。
• Red squirrels are now very rare in Britain.
  红色的松鼠在英国已十分罕见了。