飞机的引擎发出隆隆的声响。

The airplane's engines are ___roaring.

我们在动物园听到了狮子在围栏里咆哮。

We heard the lion ___roaring inside its enclosure at the zoo.

这家餐厅在周末总是人声鼎沸，生意非常红火。

The restaurant is always ___roaring with customers on weekends.