英语 词汇题 较难

电子邮件写作规范 — 英语词汇题

剑桥商务英语(BEC) 商务写作 AI 三重审校通过

题目
选词填空(商务电子邮件写作规范):In a formal business email, the ______ line should briefly summarize the purpose of the message so that the recipient can grasp its content at a glance. A. heading B. subject C. caption D. title