Radioactive standard
[化] 放射性标准源
🧩 词语组成解析
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;
🗣️ 情景例句
He has to drive for twenty minutes to get from his house to his office.
从他的家到他的办公室有20分钟的车程。
I'm sorry,but both of them are busy right now.
很抱歉他们现在很忙。
That makes sense.
那可以理解。