英語(yǔ)聽力：恐龍之戰(zhàn)之極限生存—15

　　But with both parents out searching for food,the nest is left unguarded and exposed.

　　Triceratops may be a plant eater, but with a defenseless baby T. Rex around, it'll make an exception.

　　Quetzalcoatlus is the largest flying carnivore in Earth's history. It eats 4-5 kilos of flesh every day, nearly the weight of two hatchlings combined.

　　To survive, these chicks will have to keep a very low profile.

　　A Tyrannosaurus Rex can pinpoint the exact location of an odor.

　　Soon he's headed straight for the dead Triceratops.

　　The sense of smell was powerful in the T. Rex.

　　The nerve that goes to the sense of smell is the biggest nerve the dinosaur had.

　　They could probably tell not just if there was dinosaur that had walked past.

　　They could be able to tell that that dinosaur walked past 2 and half hours ago.

　　T. Rex's nose, like a laser-guidance system, and leads him directly to his target.

　　But what these advanced senses do not tell him is how his Triceratops died in the first place. The answer to that question is found in the mouth of another T. Rex.

　　This predator's massive jaws,with their bone-crushing teeth able to bite down with enough force to bend steel,hold the hidden danger.

　　It's quite likely that the teeth of carnivorous dinosaurs have rotting meat, little bits of it, caught in their teeth, and therefore a lot of bacteria and therefore an infectious bite.

　　The bacteria would have given T. Rex permanent bad breath.

　　There would be many reasons you would not want to be around the mouth of a T. Rex,and smell would have been one of them.

　　That bacteria means that any bite that draws blood can cause a life-threatening infection.