He agreed to their visit with the proviso that they should stay no longer than one week.

他同意他们来做客，但条件是逗留不得超过一周。

《牛津词典》

So overall (and with the huge proviso that you do not count the fossil fuel used to farm the stuff) biofuels are carbon-neutral.

因此，总体来讲，生物燃料是属于碳中性的，但条件是人们不会去计算制造生物燃料所要耗费的化石燃料。

youdao

With the centralisers, an earlier decision—to run only one pipe down the well, making it easier for gas and oil to get up—had been taken with the proviso that extra care would be needed in cementing.

在有关粘合问题上的一项早期的决定——油井下只有一根管道，使得天然气和石油抽上变得更容易——附有条件是粘合的时候需要额外小心。

youdao

With one proviso: that it is also the business of his relatives and, especially, his dependants.

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The subsidy was included in the 2003 law with the proviso that the government payments would begin to phase out in 2010.

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His biggest gift came in 1997 with the proviso that he be allowed to send his finance chief to scrutinize Liberty's books.

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