foolishly

He foolishly left his car keys inside the vehicle and locked the doors by mistake.

(Chinese) 他愚蠢地把车钥匙留在车里，还误锁了车门。

The investor foolishly put all of his life savings into a business he didn't understand.

(Chinese) 这位投资者愚蠢地将毕生积蓄投入到一个他不了解的行业中。