In general, new laws are not retroactive.

一般来讲，新法都是不溯及既往的。

The newly amended law has no retroactive effect.

新修订的法律并无追溯效力。

We will talk about the retroactive law next class.

下节课我们将讨论追溯法。

It isn't yet clear whether the new law is retroactive.

这项新法令是否具有追溯效力还不清楚

They discussed forgetting in short-term memory and retroactive inhibition.

他们探讨了短时记忆的遗忘和倒摄抑制。

This law is not retroactive.

此法不溯及既往。

Couldn't we make it retroactive?

难道我们可以把它追溯？

This is not retroactive.

但是这项法规并无追溯效力。

Retroactive taxes and personal threats?

追补加税和个人威胁？