1. The mouse is a small gnawer that can cause damage to household items.
这只老鼠是一种小型的啃咬者，可能会给家具造成损坏。

2. The beaver is a large gnawer that builds dams and lodges with its sharp teeth.
河狸是一种大型的啃咬者，它用锋利的牙齿筑起水坝和栖息处。