🧩 词语组成解析
radioactivity
[,redɪoæk'tɪvəti]
n. 放射（性）;辐射能;
radio光线+act行动，做+ivity表示情况、状态、“...性”、“...力” →放射性；[核] 放射能力；[核] 放射现象
unit
['ju:nit]
n. 单位，单元;装置;个体;[数]单位数;
🗣️ 情景例句
Follow me, please.
请跟我来。
If you sell the cow, you sell her milk too.
蚀了本也输了利。
It looks a bit like a deer. There's its head and there are its feet.
它看起来有点像鹿，那是鹿头，那是鹿脚。