Singleton substitution
[计] 唯一替换
🧩 词语组成解析
n. 一个, 独生子, 独身
substitution
[ˌsʌbsti'tju:ʃən]
n. 代替;代用;替换;<化>取代（作用）;
🗣️ 情景例句
Take care.
慢走。
It's essential to choose the right means of transportation.
选择合适的运输方式很重要。
In a few days I was learning and enjoying it like any child.
几天之后，我像一个孩子那样学习起来--而且学得很开心。