第一句：Can you take a message for me?
能帮我留言吗？

A: Good morning. ABC company.
早上好，ABC公司。
B: Hello. This is Dick Smith of DEF Company. May I speak to Mr. John Black, please?
你好，我是DEF公司的迪克·史密斯。我可以和约翰·布莱克先生通话吗？
A: I'm sorry. Mr. Black, please?
对不起，布莱克先生刚出去。
B: Can you take a message for me?
能帮我留言吗？

第二句：I think it's better for me to leave a message.
我觉得还是留下一个口信比较好。

A: Could you call back later or would you mind leaving a message?
您可以过一会儿再打来或者给他留言吗？
B: I think it's better for me to leave a message. But it's more important and urgent. Please make sure he gets this message.
我觉得还是留下一个口信比较好。不过这件事很紧急，请一定将留言传达给他。
A: I see. I'm sure to pass your message to Mr. Black.
明白了，我一定把您的留言传达给布莱克先生。

其他表达法：

Would you mind telling him that due to some sudden changes, do not fill out any orders?
你可以告诉他，由于意外变化请勿发货吗？

Let me repeat the message.
我再重复一遍留言。