She had known Max for some years now, but he was still pretty much an unknown quantity.

她现在认识马克斯也好几年了，但是他仍然是个大大的未知数。

《柯林斯英汉双解大词典》

The Frenchman was an unknown quantity when he arrived in north London back in 1996.

1996年，当他初到北伦敦时，这个法国人还只不过是个未知数而已。

youdao

Youth is the smile of the future in the presence of an unknown quantity, which is itself.

青春就是未来在向一个陌生人微笑，而这陌生人就是自己。

youdao

But in some key repertoire for the Philharmonic, Bruckner and Schumann for instance, he is an unknown quantity.

ECONOMIST: Why Berlin��s musicians don��t need a maestro

At 18, Prince Hamzeh is an unknown quantity (just as King Hussein was when he became king, aged 17).

ECONOMIST: How indispensable is King Hussein?

"He's seen as an unknown quantity, and VCs love for things to be very much in control, " says Facebook cofounder Dustin Moskovitz.

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