The cheering inside the stadium was unbelievable. 体育场内的噪声大得令人难以置信。

Williams played an unbelievable match (=she played very well) . 威廉姆斯在比赛中打得棒极了。

The acting was good, although the plot was unbelievable. 表演很精彩，不过情节不真实。

The food was unbelievably cheap. 食品便宜得令人难以置信。