每日口說挑戰 啃吧孩子！海狸怎麼築水壩？ (How Beavers Build Dams | Leave it to Beavers

今日挑戰句子

The beavers' incisors are strengthened with iron, which makes them orange.

海狸的門牙含有鐵質，導致它們是橘色的。