Backdoor
a. 秘密的
✅ 同义词
🗣️ 情景例句
I want to have a personal interview with him.
我想和他直接面谈。
The truest politeness comes from sincerity.
真正的殷勤出于真诚。
he always insisted that it should be written out in full.
但他还是坚持要求将信的全文写在信纸上。