Challenge-response
挑战-应答
🧩 词语组成解析
challenge
['tʃælɪndʒ]
n. 挑战;盘问;质疑;怀疑;
vt. 质疑;向…挑战;
vi. 提出挑战，要求竞赛（或竞争）;驳斥;
🗣️ 情景例句
Many hands make light work.
人多好办事。
I was surprised to see you here.
我想不到在这里碰到了你。
How often do you write?
你们隔多久写信？