Back focal length
[计] 后焦距
🧩 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;
focal
['fəukəl]
adj. 焦点的，有焦点的;集中在点上的;病灶的，病灶性的;
🗣️ 情景例句
He was ill at ease at her birthday party.
他在她的生日宴聚会中心神不宁。
I did composition last month.
我上个月做作文。
I could answer sixteen of the question.They were very easy.
其中的16道题。这些题很容易。