Radioactive standard

radioactive ['redɪo'æktɪv]

adj. 放射性的;

radio光线+act行动，做+ive有...性质的、有...作用的 →放射性的

standard ['stændɚd]

n. 标准，规格;旗，军旗;度量衡标准;直立支柱; adj. 标准的，合格的;普遍的，一般的;公认为优秀的;

Is that you, Susan?

是你吗， Susan？

A book that remains shut is but a block.

有书闭卷不阅读，无异是一块木头。

The only way that they can preserve their history is to recount it as sagas -- legends handed down from one generation of another.These legends are useful because they can tell us something about migrations of people who lived long ago, but none could wri

他们保存历史的唯一办法是将历史当作传说讲述，由讲述人一代接一代地将史实描述为传奇故事口传下来。