have a field day 忙了一整天；痛快地玩了一阵子；获得空前的机会

【例句】
I suspect that the lawyers are going to have a field day before it's all sorted out.
我想律师们要好好忙活一通才能把一切都弄停当了。

If the newspapers get hold of this scandal, they'll really have a field day!
报纸如果能抓住这件丑闻，那可就有机会大做文章了。