Substitution cipher
n.代用密码（或记号）
🧩 词语组成解析
substitution
[ˌsʌbsti'tju:ʃən]
n. 代替;代用;替换;<化>取代（作用）;
cipher
['saifə]
n. 密码;零;不重要的人;无价值的东西;
vt. 用密码书写;
🗣️ 情景例句
Are you through with your work?
你工作做完了吗？
I don't feel very well this morning.
我今早感到不很好。
Five days ago, the policeman told him, the bicycle was picked up in a small village four hundred miles away.
那位警察对他说，那辆自行车是5天前在400英里外的一个小村里发现的，