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
we can ship the goods one month ahead of time.
我们可以提前一个月起运。
I finished working at 5:30 and went home.
我在5:30完成了工作并且回家。
carrying with him in his pocket what remained of a bottle of medicine formerly prescribed for an indisposition of Mrs.Carlyle's.
衣袋里装上了一瓶他妻子不舒服时吃剩下的药。