我必须立即和他谈话，这至关重要。

It is ___imperative that I speak with him at once.

再次见到她的父亲并向他揭露真相是至关重要的。

It was ___imperative to see her father again and confront him with the truth.

在这场危机中，迅速做出决定是至关重要的。

In this crisis, it is ___imperative to make a swift decision.