B：No， that's OK. I'll call back. 不用了。 我会再打过来的。
A：I don't know， sir. Would you like to leave a message？ 我不知道，先生。 您需要留个口信吗？
A：I'm sorry， he's in a meeting. May I take a message？ 对不起，他在开会。 要留个口信吗？
B：My name is Lance Stevens. May I speak to your Customer Service manager？ 我是Lance Stevens，请你们的客户服务部经理接电话，好吗？
A：Good morning， ABC Computers， Sally speaking. Can I help you？ 早上好。 ABC公司，我是Sally，请问您找那位？
A：Your table is ready, sir. Please step this way. 你们的桌子已经准备好了，先生，太太。 请往这边走。
A：I’m sorry. The restaurant is full now. You have to wait for about half an hour. Would you care to have a drink at the lounge until a table is available? 很抱歉，餐厅已经满座了。 约要等30 分钟才会有空桌。 你们介意在休息室喝点东西直至有空桌吗？
A：Do you have a reservation, sir? 请问您订位了吗？先生，太太？
People sometimes say sir as a very formal and polite way of addressing a man whose name they do not know or a man of superior rank. For example, a shop assistant might address a male customer as sir .
e.g. Excuse me sir, but would you mind telling me what sort of car that is?...
e.g. Good afternoon to you, sir.
Sir is the title used in front of the name of a knight or baronet.
e.g. She introduced me to Sir Tobias and Lady Clarke.
You use the expression Dear sir at the beginning of a formal letter or a business letter when you are writing to a man. You use Dear sirs when you are writing to an organization.
e.g. Dear Sir, Your letter of the 9th October has been referred to us.
尊敬的先生，您 10 月 9 日的来信已转交我处。