"have a field day" in Chinese (Simplified)
非常开心大肆行动借机发挥
Definition
指非常开心、尽情享受，通常因获得新机会或利用某个情形而大肆行动。常用于某人因他人失误或新鲜事物而感到高兴时。
Usage Notes (Chinese (Simplified))
属于非正式、口语用法，常带讽刺或调侃意味，多用于新闻、大事件或某人闹乌龙时。与体育现场无关。媒体报道常用：‘媒体对此大肆渲染’。
Examples
The kids will have a field day at the amusement park.
孩子们在游乐园一定会**玩得非常开心**。
If you bring cake to school, your classmates will have a field day.
如果你带蛋糕去学校，同学们会**开心极了**。
The media will have a field day if they find out about the mistake.
媒体如果发现这个错误，一定会**大肆报道**。
When the celebrities arrived, the photographers really had a field day.
明星一到场，摄影师们就**玩得不亦乐乎**。
The students had a field day making fun of the teacher's silly hat.
学生们**抓住机会嘲笑**老师那顶滑稽的帽子。
Reporters will have a field day with this political scandal.
记者们会借这个政治丑闻**大做文章**。