科学家们通过化石研究剑齿虎的生活习性。

Scientists study the habits of ___saber-toothed cats through fossils.

社交媒体上的网络喷子就像一群凶猛的剑齿虎，随时准备攻击任何人。

Online trolls on social media are like a pack of ___saber-toothed predators, ready to attack anyone.