对不认识的人要称呼他们的姓：用他们的头衔(先生、女士、博士等)加上他们的姓。

Use last names with people you do not know: Address people using their title (Mr, Ms, Dr) and their last names.

youdao

当发现2006他他的博士论文有大部分引用并没有来源时，他决定放弃他的博士头衔。

He renounced the title days after the discovery that much of his 2006 doctoral thesis was copied from other sources without proper attribution.

youdao

科技部也扮演猎头角色并为那些信息科技公司寻找拥有博士头衔的雇员，同时为这些雇员支付部分薪水。

It also ACTS as a headhunter for information-technology firms seeking employees with PhDs, and will pay part of the salaries of such recruits.

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