stifle的現在分詞是哪個

例句：

The government failed to stifle the unrest.

政府沒有制止住動亂。

They hope the new rules will not stifle creativity.

他們希望新規則不會壓制創意。

These measures will have the effect of stifling competition.

這些措施會產生扼殺競爭的後果。