This is certainly a theoretical risk but in practice there is seldom a problem.

这在理论上肯定有风险，但在实践中却很少出问题。

《柯林斯英汉双解大词典》

The other alternatives are attractive in theory but in practice are either impractical or offer only marginal improvements.

其他替代方案在理论上很有吸引力，但在实践中要么不切实际，要么只能提供微不足道的改进。

youdao

Prisoners have legal rights, but in practice these rights are not always respected.

囚犯虽有合法的权利，但实际上这些权利常未受到尊重。

《牛津词典》

In break from past practice, Blake said Clinton will not visit Pakistan on this trip but would do so on another trip in the fall, reportedly in October.

VOA: standard.2009.07.15

But in practice, it's really easy to say this person doesn't match in there but does match up along so many dimensions.

但在现实生活中，人们总是会找这样的借口,这个人在这一方面不行，可还有很多方面适合。

斯坦福公开课 - 扎克伯格谈Facebook创业过程课程节选

but I think it's, you know, a good practice, especially to be learned here in the United States, too.

但是我觉得这样，是很好的练习，特别是在美国做生意也有学问。

学习外语的重要性 - SpeakingMax英语口语达人

Economic analysis is itself value-free, but in practice it encourages a cosmopolitan interest in natural equality.

FORBES: A Radicaltarian Look At Getting Over The Moral Limits Of Economics

They may articulate what is right, but in practice it is a different story.

BBC: Dementia care: Your stories

But in practice, Google has let plenty of malicious apps into its Android Market before.

FORBES: Researchers Show Android Vulnerable To App-Hijacking Attacks