那只大袋鼠发出响亮的叫声，吓跑了附近的动物。

The big kangaroo made a loud ___roo-roo that scared away nearby animals.

那辆改装过的摩托车发动时发出响亮的轰鸣声。

The modified motorcycle made a loud ___roo-roo when he started the engine.