It seemed like a good idea before we started, but in practice it was a disaster.

在我们动手之前这似乎是个好主意 但实际上却是场灾难

In practice, however, such an attitude is counterproductive.

然而在实际中，这种态度会适得其反。

I agree with it in principle but I doubt if it will happen in practice.

我原则上是同意它的，但我怀疑在实践中它是否会发生。

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。

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。

Achieving these goals is relatively easy in theory, yet quite difficult in practice.

实现这些目标从理论上说比较容易，但在实践上却相当困难。