I cannot do it; not but what a younger man might be able to do it.

我不能做, 但也许年轻一点的人能做.

《简明英汉词典》

Speak not but what may benefit others or yourself; avoid trifling conversation.

不说与人与己不利的话, 不作无谓交谈.

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B : No. Of course not. But what for?

当然不介意. 但为什么 呀 ?

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Silence: Speak not but what may benefit others or yourself ; avoid trifling conversation.

缄默: 避免无聊 闲扯,言谈必须对人有益.

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Silence: Speak not but what may benefit others or yourself. Avoid trifling conversation.

沉默: 只说那些能让他人或自己受益的话. 避免闲聊.

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SILENCE. Speak not but what may benefit others or yourself; avoid trifling conversation.

慎言. 要说于人于己有利的话, 注意沟通方式.

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