sine qua non

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But voters’ ability to throw the rascals out at regular intervals is still the indispensable sine qua non.
不过，选民能够定期摒弃一些流氓无赖的能力仍是不可或缺的必要条件。
Absorbed attention — the capacity to delay other gratifications to focus on one thing at a time — is the sine qua non of achieving and sustaining excellence at anything.
全神贯注——暂时忽略其他需要，把注意力集中在一件事情上的能力——是一个人在任何事情上取得卓越成就并持续发展的必要条件。
The code's sine qua non is honour, or nang, a word which, according to Sir Olaf Caroe, an imperial scholar of the Pushtuns, contains a mythical sense of chastity.
该规范的先决要素是荣誉（honour[font=宋体]），或说是“nang[font=宋体]”，根据普什图人的皇家学者奥拉夫·卡罗爵士（Sir Olaf Caroe[font=宋体]）的说法，该词包含了某种贞节（chastity[font=宋体]）的神秘感。

And both of those ventures had distribution, the sine qua non of success in cable.
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Above all, very few of the findings have been replicated, the sine qua non of science.
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First was the greatness of 1960s growth, the sine qua non of postwar prosperity.
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A sine qua non is something that is essential if you want to achieve a particular thing.