But Howells acknowledged the government cannot guarantee that some of the terror suspects picked up and held in other countries did not have their human rights abused.

VOA: standard.2009.08.10

Hopefully within two years, probably not next year, but within two years, there will be positive psychology class offered, but I certainly cannot guarantee it.

但愿两年内，明年可能性不大，但是两年内，学校会再次开设积极心理学课程，但我无法保证。

哈佛公开课 - 幸福课课程节选

There were words in there--they said something--of course, we cannot guarantee that they won't go up in value but historically they have always done it or something like that.

他们在文中吹嘘...当然,我们不能保证金币不会升值,但金币的历史行情趋势始终向上

耶鲁公开课 - 金融市场课程节选