Jan realised later that her behaviour had been very foolish.简后来才意识到她的行为非常愚蠢。Firing coach Barker would be a very foolish mistake.解雇巴克教练会是个非常愚蠢的错误。It was a pretty daft idea anyway.不管怎么说这都是一个非常愚蠢的想法。I provoked him into doing something really stupid.在我的刺激下他做了件非常愚蠢的事。