Network providers do not guarantee a certain quality of service, but merely promise to do their best. That may not matter for personal e-mails, but it does for time-sensitive data such as video.

网络提供者们不担保某种程度的服务质量，仅承诺将尽力而为，这可能对个人电邮不算什么，但是对时间敏感的数据比如视频就很重要了。

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A: I can promise you that, if you buy our product, you will be getting quality.

我可以向你保证，如果你买了我们的产品，你会得到好品质。

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The quality of the software can be improved based on analyzing the results of such attributes. This is the promise of ODC.

通过分析这些属性的结果可以提高软件的质量，这是ODC的承诺。

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These retailers consistently deliver on a promise of quality, and this approach has delivered strong returns for their businesses.

FORBES: Retailers: Who Do You Trust?

Just as people have come to trust the Napa Valley name and its overall promise of quality, the same should go for Central Otago.

FORBES: New Zealand Wine's Need For Nudity

Despite these notable achievements, the international community is still not on track to deliver on the promise of quality basic education for all by 2015.

UNESCO: CULTURE