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[化] 反馈作用
🧩 词语组成解析
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[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
Next time you are in town, drop me a line.
下次你在城里的时候给我写信吧。
Good. Let's go to the office.
好的，我们去办公室吧。
He passed his exams, and even better, when he left university he had earned enough money to start his own business, offering guide services to tourists.
他考试过关了，更惬意的是，他大学毕业时，所赚的钱足够他开始经营自己的行业--为游客提供导游服务。