Following the long line of students at the Field Museum, Caleb and Evan filed behind, taking in all of the sights. The day had already been a long morning of viewing exhibits and listening to mumbling tour guides. Evan made his signature sigh of boredom, and Chris knew that meant something mischievous was about to happen. Chris felt a tap on his shoulder, and his heart began to beat a little bit faster. There was nothing good that came from a tap from Evan. They had been in trouble plenty of times, and Chris was not looking forward to this adventure. He was hoping that their teacher would turn a blind eye to whatever Evan was concocting in his head.
Looking over his shoulder, Chris heard Evan whisper, "Hey, we should head off on our own. There’s so much more to see than this gem place that we have to be. Come on. We’ll sneak out once we have to turn that corner."
Okay, how do I get out of this? Chris thought.
"All right. Here’s our opening. Act naturally, Chris," Evan instructed, as he began to walk toward another exhibit.
Evan led Chris into an exhibit that seemed to be too good to be true. There were large displays of dinosaurs from the infamous Tyrannosaurus Rex to the gigantic Apatosaurus. Chris gaped at the dinosaurs in amazement because he had been a fan of the Jurassic period since he was a little kid.
"Look, Chris, there’s an authentic replica of the Allosaurus here. It seems fiercer in person than in the pictures that book we used to read when we were kids," Evan reflected as he stared at the dinosaur intently.
“It sure does,” Chris replied, awestruck. It’s a good thing that followed Evan or else I would never have had the chance to see this specimen.

Which sentence from the passage contains an oxymoron?