There is nothing inherently improbable in the idea.

这想法什么能的。

It is improbable that she will go.

她见得会走。

These new facts make the theory improbable.

这些新出现的实使这一理论变得荒谬。

The film tells the improbable story of a monkey that becomes a politician.

这部影片讲述了一能发生的故：一只猴子变成了一名政治家。

This is highly improbable.

这是完全能的。