Back mutation
回复突变
🧩 词语组成解析
back
[bæk]
n. 背，背部;背面，反面;后面，后部;（椅子等的）靠背;
vt. 使后退;支持;加背书于;下赌注于;
vi. 后退;倒退;
adj. 背部的;后面的;以前的;拖欠的;
adv. 以前;向后地;
🗣️ 情景例句
Maybe soon.
也许很快就会。
I didn't think I'd see you here.
没想到会在这碰上你。
You've done very well. It's a pity you missed the sports meeting last week.
你学得不错嘛。很可惜，你错过了上周的运动会。