那是个愚蠢的决定。

That was an ___insane decision.

在暴风雨中把派对安排在户外真是个愚蠢的主意。

It was an ___insane idea to hold the party outdoors in a storm.

不系安全带开车简直是愚蠢。

Driving without a seatbelt is just ___insane.